diff --git a/bin/migrate-from-phpexcel b/bin/migrate-from-phpexcel
index 416c3a42..51c60d49 100755
--- a/bin/migrate-from-phpexcel
+++ b/bin/migrate-from-phpexcel
@@ -1,6 +1,8 @@
 #!/usr/bin/env php
 <?php
+use PhpOffice\PhpSpreadsheet\Helper\Migrator;
+
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$migrator = new \PhpOffice\PhpSpreadsheet\Helper\Migrator();
+$migrator = new Migrator();
 $migrator->migrate();
diff --git a/docs/Examples/Calculations/Database/DAVERAGE.php b/docs/Examples/Calculations/Database/DAVERAGE.php
index b54a7d1d..c2d31a6a 100644
--- a/docs/Examples/Calculations/Database/DAVERAGE.php
+++ b/docs/Examples/Calculations/Database/DAVERAGE.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DCOUNT.php b/docs/Examples/Calculations/Database/DCOUNT.php
index 2cd0661d..d7bf2045 100644
--- a/docs/Examples/Calculations/Database/DCOUNT.php
+++ b/docs/Examples/Calculations/Database/DCOUNT.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DGET.php b/docs/Examples/Calculations/Database/DGET.php
index d64b1d6e..819120cb 100644
--- a/docs/Examples/Calculations/Database/DGET.php
+++ b/docs/Examples/Calculations/Database/DGET.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DMAX.php b/docs/Examples/Calculations/Database/DMAX.php
index 58d2f039..4fe13da6 100644
--- a/docs/Examples/Calculations/Database/DMAX.php
+++ b/docs/Examples/Calculations/Database/DMAX.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DMIN.php b/docs/Examples/Calculations/Database/DMIN.php
index e4fb7658..b765c061 100644
--- a/docs/Examples/Calculations/Database/DMIN.php
+++ b/docs/Examples/Calculations/Database/DMIN.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DPRODUCT.php b/docs/Examples/Calculations/Database/DPRODUCT.php
index 382227df..4cf234d3 100644
--- a/docs/Examples/Calculations/Database/DPRODUCT.php
+++ b/docs/Examples/Calculations/Database/DPRODUCT.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DSTDEV.php b/docs/Examples/Calculations/Database/DSTDEV.php
index e1273e5a..8aeaf2d8 100644
--- a/docs/Examples/Calculations/Database/DSTDEV.php
+++ b/docs/Examples/Calculations/Database/DSTDEV.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DSTDEVP.php b/docs/Examples/Calculations/Database/DSTDEVP.php
index 3af791bb..0a562c65 100644
--- a/docs/Examples/Calculations/Database/DSTDEVP.php
+++ b/docs/Examples/Calculations/Database/DSTDEVP.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DVAR.php b/docs/Examples/Calculations/Database/DVAR.php
index 44e63994..b49020bf 100644
--- a/docs/Examples/Calculations/Database/DVAR.php
+++ b/docs/Examples/Calculations/Database/DVAR.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/Database/DVARP.php b/docs/Examples/Calculations/Database/DVARP.php
index c630e731..83d06fba 100644
--- a/docs/Examples/Calculations/Database/DVARP.php
+++ b/docs/Examples/Calculations/Database/DVARP.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/DateTime/DATE.php b/docs/Examples/Calculations/DateTime/DATE.php
index 1af05e3e..5b0a8717 100644
--- a/docs/Examples/Calculations/DateTime/DATE.php
+++ b/docs/Examples/Calculations/DateTime/DATE.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/DateTime/DATEVALUE.php b/docs/Examples/Calculations/DateTime/DATEVALUE.php
index 42996a4e..437b6aa8 100644
--- a/docs/Examples/Calculations/DateTime/DATEVALUE.php
+++ b/docs/Examples/Calculations/DateTime/DATEVALUE.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/DateTime/TIME.php b/docs/Examples/Calculations/DateTime/TIME.php
index 9c206304..588eadf9 100644
--- a/docs/Examples/Calculations/DateTime/TIME.php
+++ b/docs/Examples/Calculations/DateTime/TIME.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Calculations/DateTime/TIMEVALUE.php b/docs/Examples/Calculations/DateTime/TIMEVALUE.php
index c5745cc2..26996b61 100644
--- a/docs/Examples/Calculations/DateTime/TIMEVALUE.php
+++ b/docs/Examples/Calculations/DateTime/TIMEVALUE.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -22,7 +24,7 @@ date_default_timezone_set('Europe/London');
 require_once __DIR__ . '/../../../../src/Bootstrap.php';
 
 // Create new PhpSpreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 // Add some data
diff --git a/docs/Examples/Reader/exampleReader01.php b/docs/Examples/Reader/exampleReader01.php
index 9ef1f565..d20207a2 100644
--- a/docs/Examples/Reader/exampleReader01.php
+++ b/docs/Examples/Reader/exampleReader01.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -16,14 +18,14 @@ date_default_timezone_set('Europe/London');
 <body>
 
 <h1>PhpSpreadsheet Reader Example #01</h1>
-<h2>Simple File Reader using \PhpOffice\PhpSpreadsheet\IOFactory::load()</h2>
+<h2>Simple File Reader using IOFactory::load()</h2>
 <?php
 
 require_once __DIR__ . '/../../../src/Bootstrap.php';
 
 $inputFileName = './sampleData/example1.xls';
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory to identify the format<br />';
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($inputFileName);
+$spreadsheet = IOFactory::load($inputFileName);
 
 echo '<hr />';
 
diff --git a/docs/Examples/Reader/exampleReader02.php b/docs/Examples/Reader/exampleReader02.php
index b98b860d..9d301f69 100644
--- a/docs/Examples/Reader/exampleReader02.php
+++ b/docs/Examples/Reader/exampleReader02.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Reader\Xls;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -24,7 +26,7 @@ require_once __DIR__ . '/../../../src/Bootstrap.php';
 $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using \PhpOffice\PhpSpreadsheet\Reader\Xls<br />';
-$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xls();
+$reader = new Xls();
 //	$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xlsx();
 //	$reader = new \PhpOffice\PhpSpreadsheet\Reader\Xml();
 //	$reader = new \PhpOffice\PhpSpreadsheet\Reader\Ods();
diff --git a/docs/Examples/Reader/exampleReader03.php b/docs/Examples/Reader/exampleReader03.php
index dbd584b4..07dfa7ae 100644
--- a/docs/Examples/Reader/exampleReader03.php
+++ b/docs/Examples/Reader/exampleReader03.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -16,7 +18,7 @@ date_default_timezone_set('Europe/London');
 <body>
 
 <h1>PhpSpreadsheet Reader Example #03</h1>
-<h2>Simple File Reader using the \PhpOffice\PhpSpreadsheet\IOFactory to Return a Reader</h2>
+<h2>Simple File Reader using the IOFactory to Return a Reader</h2>
 <?php
 
 require_once __DIR__ . '/../../../src/Bootstrap.php';
@@ -31,7 +33,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 $spreadsheet = $reader->load($inputFileName);
 
 echo '<hr />';
diff --git a/docs/Examples/Reader/exampleReader04.php b/docs/Examples/Reader/exampleReader04.php
index 2267a9df..d26d6525 100644
--- a/docs/Examples/Reader/exampleReader04.php
+++ b/docs/Examples/Reader/exampleReader04.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -16,18 +18,18 @@ date_default_timezone_set('Europe/London');
 <body>
 
 <h1>PhpSpreadsheet Reader Example #04</h1>
-<h2>Simple File Reader using the \PhpOffice\PhpSpreadsheet\IOFactory to Identify a Reader to Use</h2>
+<h2>Simple File Reader using the IOFactory to Identify a Reader to Use</h2>
 <?php
 
 require_once __DIR__ . '/../../../src/Bootstrap.php';
 
 $inputFileName = './sampleData/example1.xls';
 
-$inputFileType = \PhpOffice\PhpSpreadsheet\IOFactory::identify($inputFileName);
+$inputFileType = IOFactory::identify($inputFileName);
 echo 'File ',pathinfo($inputFileName, PATHINFO_BASENAME),' has been identified as an ',$inputFileType,' file<br />';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with the identified reader type<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 $spreadsheet = $reader->load($inputFileName);
 
 echo '<hr />';
diff --git a/docs/Examples/Reader/exampleReader05.php b/docs/Examples/Reader/exampleReader05.php
index 807e910d..ff72be92 100644
--- a/docs/Examples/Reader/exampleReader05.php
+++ b/docs/Examples/Reader/exampleReader05.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -29,7 +31,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Turning Formatting off for Load<br />';
 $reader->setReadDataOnly(true);
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader06.php b/docs/Examples/Reader/exampleReader06.php
index 84675c17..ccc59373 100644
--- a/docs/Examples/Reader/exampleReader06.php
+++ b/docs/Examples/Reader/exampleReader06.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -29,7 +31,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading all WorkSheets<br />';
 $reader->setLoadAllSheets();
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader07.php b/docs/Examples/Reader/exampleReader07.php
index 0463f37b..cde1c409 100644
--- a/docs/Examples/Reader/exampleReader07.php
+++ b/docs/Examples/Reader/exampleReader07.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -30,7 +32,7 @@ $inputFileName = './sampleData/example1.xls';
 $sheetname = 'Data Sheet #2';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading Sheet "',$sheetname,'" only<br />';
 $reader->setLoadSheetsOnly($sheetname);
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader08.php b/docs/Examples/Reader/exampleReader08.php
index c5e9b39d..0a739f75 100644
--- a/docs/Examples/Reader/exampleReader08.php
+++ b/docs/Examples/Reader/exampleReader08.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -30,7 +32,7 @@ $inputFileName = './sampleData/example1.xls';
 $sheetnames = ['Data Sheet #1', 'Data Sheet #3'];
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading Sheet',((count($sheetnames) == 1) ? '' : 's'),' "',implode('" and "', $sheetnames),'" only<br />';
 $reader->setLoadSheetsOnly($sheetnames);
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader09.php b/docs/Examples/Reader/exampleReader09.php
index e2464447..8dde497c 100644
--- a/docs/Examples/Reader/exampleReader09.php
+++ b/docs/Examples/Reader/exampleReader09.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -29,7 +32,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 $sheetname = 'Data Sheet #3';
 
-class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+class MyReadFilter implements IReadFilter
 {
     public function readCell($column, $row, $worksheetName = '')
     {
@@ -47,7 +50,7 @@ class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 $filterSubset = new MyReadFilter();
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading Sheet "',$sheetname,'" only<br />';
 $reader->setLoadSheetsOnly($sheetname);
 echo 'Loading Sheet using filter<br />';
diff --git a/docs/Examples/Reader/exampleReader10.php b/docs/Examples/Reader/exampleReader10.php
index 965a1bb2..f62c98d93 100644
--- a/docs/Examples/Reader/exampleReader10.php
+++ b/docs/Examples/Reader/exampleReader10.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -29,7 +32,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 $sheetname = 'Data Sheet #3';
 
-class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+class MyReadFilter implements IReadFilter
 {
     private $_startRow = 0;
 
@@ -59,7 +62,7 @@ class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 $filterSubset = new MyReadFilter(9, 15, range('G', 'K'));
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading Sheet "',$sheetname,'" only<br />';
 $reader->setLoadSheetsOnly($sheetname);
 echo 'Loading Sheet using configurable filter<br />';
diff --git a/docs/Examples/Reader/exampleReader11.php b/docs/Examples/Reader/exampleReader11.php
index 5435629a..2b7225a9 100644
--- a/docs/Examples/Reader/exampleReader11.php
+++ b/docs/Examples/Reader/exampleReader11.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -28,8 +31,8 @@ $inputFileType = 'Xls';
 //	$inputFileType = 'Gnumeric';
 $inputFileName = './sampleData/example2.xls';
 
-/**  Define a Read Filter class implementing \PhpOffice\PhpSpreadsheet\Reader\IReadFilter  */
-class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+/**  Define a Read Filter class implementing IReadFilter  */
+class chunkReadFilter implements IReadFilter
 {
     private $_startRow = 0;
 
@@ -60,7 +63,7 @@ class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 
 echo '<hr />';
 
diff --git a/docs/Examples/Reader/exampleReader12.php b/docs/Examples/Reader/exampleReader12.php
index 673b2f14..50580f2a 100644
--- a/docs/Examples/Reader/exampleReader12.php
+++ b/docs/Examples/Reader/exampleReader12.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -28,8 +31,8 @@ $inputFileType = 'Xls';
 //	$inputFileType = 'Gnumeric';
 $inputFileName = './sampleData/example2.xls';
 
-/**  Define a Read Filter class implementing \PhpOffice\PhpSpreadsheet\Reader\IReadFilter  */
-class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+/**  Define a Read Filter class implementing IReadFilter  */
+class chunkReadFilter implements IReadFilter
 {
     private $_startRow = 0;
 
@@ -60,7 +63,7 @@ class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 
 echo '<hr />';
 
diff --git a/docs/Examples/Reader/exampleReader13.php b/docs/Examples/Reader/exampleReader13.php
index 9977a83c..c5107c87 100644
--- a/docs/Examples/Reader/exampleReader13.php
+++ b/docs/Examples/Reader/exampleReader13.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -24,7 +26,7 @@ require_once __DIR__ . '/../../../src/Bootstrap.php';
 $inputFileType = 'Csv';
 $inputFileNames = ['./sampleData/example1.csv', './sampleData/example2.csv'];
 
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 $inputFileName = array_shift($inputFileNames);
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' into WorkSheet #1 using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader14.php b/docs/Examples/Reader/exampleReader14.php
index 933be4ac..aad066dc 100644
--- a/docs/Examples/Reader/exampleReader14.php
+++ b/docs/Examples/Reader/exampleReader14.php
@@ -1,5 +1,9 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -24,8 +28,8 @@ require_once __DIR__ . '/../../../src/Bootstrap.php';
 $inputFileType = 'Csv';
 $inputFileName = './sampleData/example2.csv';
 
-/**  Define a Read Filter class implementing \PhpOffice\PhpSpreadsheet\Reader\IReadFilter  */
-class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+/**  Define a Read Filter class implementing IReadFilter  */
+class chunkReadFilter implements IReadFilter
 {
     private $_startRow = 0;
 
@@ -56,7 +60,7 @@ class chunkReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 
 echo '<hr />';
 
@@ -71,7 +75,7 @@ $reader->setReadFilter($chunkFilter)
           ->setContiguous(true);
 
 /*  Instantiate a new PhpSpreadsheet object manually  **/
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 /*  Set a sheet index  **/
 $sheet = 0;
diff --git a/docs/Examples/Reader/exampleReader15.php b/docs/Examples/Reader/exampleReader15.php
index a04a1adc..fdf38b05 100644
--- a/docs/Examples/Reader/exampleReader15.php
+++ b/docs/Examples/Reader/exampleReader15.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -21,12 +24,12 @@ date_default_timezone_set('Europe/London');
 
 require_once __DIR__ . '/../../../src/Bootstrap.php';
 
-\PhpOffice\PhpSpreadsheet\Cell::setValueBinder(new \PhpOffice\PhpSpreadsheet\Cell\AdvancedValueBinder());
+Cell::setValueBinder(new Cell\AdvancedValueBinder());
 
 $inputFileType = 'Csv';
 $inputFileName = './sampleData/example1.tsv';
 
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' into WorkSheet #1 using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 $reader->setDelimiter("\t");
 $spreadsheet = $reader->load($inputFileName);
diff --git a/docs/Examples/Reader/exampleReader16.php b/docs/Examples/Reader/exampleReader16.php
index 6e6a7583..9436bd2e 100644
--- a/docs/Examples/Reader/exampleReader16.php
+++ b/docs/Examples/Reader/exampleReader16.php
@@ -1,5 +1,8 @@
 <?php
 
+use InvalidArgumentException;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -24,8 +27,8 @@ require_once __DIR__ . '/../../../src/Bootstrap.php';
 $inputFileName = './sampleData/example_1.xls';
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory to identify the format<br />';
 try {
-    $spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($inputFileName);
-} catch (\InvalidArgumentException $e) {
+    $spreadsheet = IOFactory::load($inputFileName);
+} catch (InvalidArgumentException $e) {
     die('Error loading file "' . pathinfo($inputFileName, PATHINFO_BASENAME) . '": ' . $e->getMessage());
 }
 
diff --git a/docs/Examples/Reader/exampleReader17.php b/docs/Examples/Reader/exampleReader17.php
index f76994e9..763805ac 100644
--- a/docs/Examples/Reader/exampleReader17.php
+++ b/docs/Examples/Reader/exampleReader17.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -29,7 +31,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' using IOFactory with a defined reader type of ',$inputFileType,'<br />';
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 
 /*  Read the list of Worksheet Names from the Workbook file  **/
 echo 'Read the list of Worksheets in the WorkBook<br />';
diff --git a/docs/Examples/Reader/exampleReader18.php b/docs/Examples/Reader/exampleReader18.php
index 6688e481..9822b209 100644
--- a/docs/Examples/Reader/exampleReader18.php
+++ b/docs/Examples/Reader/exampleReader18.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -30,7 +32,7 @@ $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' information using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 $worksheetNames = $reader->listWorksheetNames($inputFileName);
 
 echo '<h3>Worksheet Names</h3>';
diff --git a/docs/Examples/Reader/exampleReader19.php b/docs/Examples/Reader/exampleReader19.php
index 5ad3e5ba..5749d1b6 100644
--- a/docs/Examples/Reader/exampleReader19.php
+++ b/docs/Examples/Reader/exampleReader19.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -30,7 +32,7 @@ $inputFileName = './sampleData/example1.xls';
 
 echo 'Loading file ',pathinfo($inputFileName, PATHINFO_BASENAME),' information using IOFactory with a defined reader type of ',$inputFileType,'<br />';
 
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 $worksheetData = $reader->listWorksheetInfo($inputFileName);
 
 echo '<h3>Worksheet Information</h3>';
diff --git a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader01.php b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader01.php
index aa9bddd7..8a6b4726 100644
--- a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader01.php	
+++ b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader01.php	
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -25,7 +27,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example1.xls';
 
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 /*  Load $inputFileName to a PhpSpreadsheet Object  **/
 $spreadsheet = $reader->load($inputFileName);
 
diff --git a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader02.php b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader02.php
index c021728c..b9cfc196 100644
--- a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader02.php	
+++ b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader02.php	
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -25,7 +27,7 @@ $inputFileType = 'Xlsx';
 $inputFileName = './sampleData/example1.xlsx';
 
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 /*  Load $inputFileName to a PhpSpreadsheet Object  **/
 $spreadsheet = $reader->load($inputFileName);
 
diff --git a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader03.php b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader03.php
index c02f51bd..81327481 100644
--- a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader03.php	
+++ b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader03.php	
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -25,7 +27,7 @@ $inputFileType = 'Xlsx';
 $inputFileName = './sampleData/example1.xlsx';
 
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 /*  Load $inputFileName to a PhpSpreadsheet Object  **/
 $spreadsheet = $reader->load($inputFileName);
 
diff --git a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader04.php b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader04.php
index 88c7f9e0..e3a71d34 100644
--- a/docs/Examples/Reading WorkBook Data/exampleWorkBookReader04.php	
+++ b/docs/Examples/Reading WorkBook Data/exampleWorkBookReader04.php	
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 error_reporting(E_ALL);
 set_time_limit(0);
 
@@ -25,7 +27,7 @@ $inputFileType = 'Xls';
 $inputFileName = './sampleData/example2.xls';
 
 /*  Create a new Reader of the type defined in $inputFileType  **/
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$reader = IOFactory::createReader($inputFileType);
 /*  Load $inputFileName to a PhpSpreadsheet Object  **/
 $spreadsheet = $reader->load($inputFileName);
 
diff --git a/samples/01_Simple.php b/samples/01_Simple.php
index d21de72e..3ba6ba05 100644
--- a/samples/01_Simple.php
+++ b/samples/01_Simple.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
-// Create new Spreadsheet object
+$spreadsheet = new Spreadsheet();
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/01_Simple_download_ods.php b/samples/01_Simple_download_ods.php
index 8e76e8cf..4031eec6 100644
--- a/samples/01_Simple_download_ods.php
+++ b/samples/01_Simple_download_ods.php
@@ -1,8 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+$helper = new Sample();
 if ($helper->isCli()) {
     echo 'This example should only be run from a Web Browser' . PHP_EOL;
 
@@ -10,7 +14,7 @@ if ($helper->isCli()) {
 }
 
 // Create new Spreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
@@ -52,6 +56,6 @@ header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); // always modifie
 header('Cache-Control: cache, must-revalidate'); // HTTP/1.1
 header('Pragma: public'); // HTTP/1.0
 
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Ods');
+$writer = IOFactory::createWriter($spreadsheet, 'Ods');
 $writer->save('php://output');
 exit;
diff --git a/samples/01_Simple_download_pdf.php b/samples/01_Simple_download_pdf.php
index dc23daa0..04c91a18 100644
--- a/samples/01_Simple_download_pdf.php
+++ b/samples/01_Simple_download_pdf.php
@@ -1,8 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+$helper = new Sample();
 if ($helper->isCli()) {
     echo 'This example should only be run from a Web Browser' . PHP_EOL;
 
@@ -12,11 +17,11 @@ if ($helper->isCli()) {
 //	Change these values to select the Rendering library that you wish to use
 //		and its directory location on your server
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_TCPDF;
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_MPDF;
+$rendererName = Settings::PDF_RENDERER_MPDF;
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_DOMPDF;
 
 // Create new Spreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
@@ -46,13 +51,13 @@ $spreadsheet->getActiveSheet()->setShowGridLines(false);
 // Set active sheet index to the first sheet, so Excel opens this as the first sheet
 $spreadsheet->setActiveSheetIndex(0);
 
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 
 // Redirect output to a client’s web browser (PDF)
 header('Content-Type: application/pdf');
 header('Content-Disposition: attachment;filename="01simple.pdf"');
 header('Cache-Control: max-age=0');
 
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Pdf');
+$writer = IOFactory::createWriter($spreadsheet, 'Pdf');
 $writer->save('php://output');
 exit;
diff --git a/samples/01_Simple_download_xls.php b/samples/01_Simple_download_xls.php
index 7bfd5cc6..71fcbc7e 100644
--- a/samples/01_Simple_download_xls.php
+++ b/samples/01_Simple_download_xls.php
@@ -1,8 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+$helper = new Sample();
 if ($helper->isCli()) {
     echo 'This example should only be run from a Web Browser' . PHP_EOL;
 
@@ -10,7 +14,7 @@ if ($helper->isCli()) {
 }
 
 // Create new Spreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
@@ -52,6 +56,6 @@ header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); // always modifie
 header('Cache-Control: cache, must-revalidate'); // HTTP/1.1
 header('Pragma: public'); // HTTP/1.0
 
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xls');
+$writer = IOFactory::createWriter($spreadsheet, 'Xls');
 $writer->save('php://output');
 exit;
diff --git a/samples/01_Simple_download_xlsx.php b/samples/01_Simple_download_xlsx.php
index 3881d4cc..45ba9bc3 100644
--- a/samples/01_Simple_download_xlsx.php
+++ b/samples/01_Simple_download_xlsx.php
@@ -1,15 +1,19 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+$helper = new Sample();
 if ($helper->isCli()) {
     echo 'This example should only be run from a Web Browser' . PHP_EOL;
 
     return;
 }
 // Create new Spreadsheet object
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
@@ -51,6 +55,6 @@ header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT'); // always modifie
 header('Cache-Control: cache, must-revalidate'); // HTTP/1.1
 header('Pragma: public'); // HTTP/1.0
 
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->save('php://output');
 exit;
diff --git a/samples/02_Types.php b/samples/02_Types.php
index 5fef248d..84bc5002 100644
--- a/samples/02_Types.php
+++ b/samples/02_Types.php
@@ -1,10 +1,16 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -70,41 +76,41 @@ $dateTimeNow = time();
 $spreadsheet->getActiveSheet()
         ->setCellValue('A9', 'Date/Time')
         ->setCellValue('B9', 'Date')
-        ->setCellValue('C9', \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($dateTimeNow));
+        ->setCellValue('C9', Date::PHPToExcel($dateTimeNow));
 $spreadsheet->getActiveSheet()
         ->getStyle('C9')
         ->getNumberFormat()
-        ->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD2);
+        ->setFormatCode(NumberFormat::FORMAT_DATE_YYYYMMDD2);
 
 $spreadsheet->getActiveSheet()
         ->setCellValue('A10', 'Date/Time')
         ->setCellValue('B10', 'Time')
-        ->setCellValue('C10', \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($dateTimeNow));
+        ->setCellValue('C10', Date::PHPToExcel($dateTimeNow));
 $spreadsheet->getActiveSheet()
         ->getStyle('C10')
         ->getNumberFormat()
-        ->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME4);
+        ->setFormatCode(NumberFormat::FORMAT_DATE_TIME4);
 
 $spreadsheet->getActiveSheet()
         ->setCellValue('A11', 'Date/Time')
         ->setCellValue('B11', 'Date and Time')
-        ->setCellValue('C11', \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($dateTimeNow));
+        ->setCellValue('C11', Date::PHPToExcel($dateTimeNow));
 $spreadsheet->getActiveSheet()
         ->getStyle('C11')
         ->getNumberFormat()
-        ->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DATETIME);
+        ->setFormatCode(NumberFormat::FORMAT_DATE_DATETIME);
 
 $spreadsheet->getActiveSheet()
         ->setCellValue('A12', 'NULL')
         ->setCellValue('C12', null);
 
-$richText = new \PhpOffice\PhpSpreadsheet\RichText();
+$richText = new RichText();
 $richText->createText('你好 ');
 
 $payable = $richText->createTextRun('你 好 吗？');
 $payable->getFont()->setBold(true);
 $payable->getFont()->setItalic(true);
-$payable->getFont()->setColor(new \PhpOffice\PhpSpreadsheet\Style\Color(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_DARKGREEN));
+$payable->getFont()->setColor(new Color(Color::COLOR_DARKGREEN));
 
 $richText->createText(', unless specified otherwise on the invoice.');
 
@@ -112,11 +118,11 @@ $spreadsheet->getActiveSheet()
         ->setCellValue('A13', 'Rich Text')
         ->setCellValue('C13', $richText);
 
-$richText2 = new \PhpOffice\PhpSpreadsheet\RichText();
+$richText2 = new RichText();
 $richText2->createText("black text\n");
 
 $red = $richText2->createTextRun('red text');
-$red->getFont()->setColor(new \PhpOffice\PhpSpreadsheet\Style\Color(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_RED));
+$red->getFont()->setColor(new Color(Color::COLOR_RED));
 
 $spreadsheet->getActiveSheet()
         ->getCell('C14')
diff --git a/samples/03_Formulas.php b/samples/03_Formulas.php
index 8896253c..752b99c8 100644
--- a/samples/03_Formulas.php
+++ b/samples/03_Formulas.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/04_Printing.php b/samples/04_Printing.php
index 4434b2f5..e8854821 100644
--- a/samples/04_Printing.php
+++ b/samples/04_Printing.php
@@ -1,10 +1,15 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooter;
+use PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooterDrawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -34,22 +39,22 @@ $spreadsheet->getActiveSheet()
 
 // Add a drawing to the header
 $helper->log('Add a drawing to the header');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooterDrawing();
+$drawing = new HeaderFooterDrawing();
 $drawing->setName('PhpSpreadsheet logo');
 $drawing->setPath(__DIR__ . '/images/PhpSpreadsheet_logo.png');
 $drawing->setHeight(36);
 $spreadsheet->getActiveSheet()
         ->getHeaderFooter()
-        ->addImage($drawing, \PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooter::IMAGE_HEADER_LEFT);
+        ->addImage($drawing, HeaderFooter::IMAGE_HEADER_LEFT);
 
 // Set page orientation and size
 $helper->log('Set page orientation and size');
 $spreadsheet->getActiveSheet()
         ->getPageSetup()
-        ->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
+        ->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
 $spreadsheet->getActiveSheet()
         ->getPageSetup()
-        ->setPaperSize(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4);
+        ->setPaperSize(PageSetup::PAPERSIZE_A4);
 
 // Rename worksheet
 $helper->log('Rename worksheet');
diff --git a/samples/07_Reader.php b/samples/07_Reader.php
index 2e7b9610..05186521 100644
--- a/samples/07_Reader.php
+++ b/samples/07_Reader.php
@@ -1,15 +1,18 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
+
 require __DIR__ . '/Header.php';
 
 // Create temporary file that will be read
 $sampleSpreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 $filename = $helper->getTemporaryFilename();
-$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($sampleSpreadsheet);
+$writer = new Xlsx($sampleSpreadsheet);
 $writer->save($filename);
 
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Xlsx', $filename, $callStartTime);
 
 // Save
diff --git a/samples/08_Conditional_formatting.php b/samples/08_Conditional_formatting.php
index 86019305..36c3aaee 100644
--- a/samples/08_Conditional_formatting.php
+++ b/samples/08_Conditional_formatting.php
@@ -1,10 +1,16 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Conditional;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -47,30 +53,30 @@ $spreadsheet->getActiveSheet()->getColumnDimension('B')->setWidth(12);
 
 // Add conditional formatting
 $helper->log('Add conditional formatting');
-$conditional1 = new \PhpOffice\PhpSpreadsheet\Style\Conditional();
-$conditional1->setConditionType(\PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS)
-        ->setOperatorType(\PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_BETWEEN)
+$conditional1 = new Conditional();
+$conditional1->setConditionType(Conditional::CONDITION_CELLIS)
+        ->setOperatorType(Conditional::OPERATOR_BETWEEN)
         ->addCondition('200')
         ->addCondition('400');
-$conditional1->getStyle()->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_YELLOW);
+$conditional1->getStyle()->getFont()->getColor()->setARGB(Color::COLOR_YELLOW);
 $conditional1->getStyle()->getFont()->setBold(true);
-$conditional1->getStyle()->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
+$conditional1->getStyle()->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
 
-$conditional2 = new \PhpOffice\PhpSpreadsheet\Style\Conditional();
-$conditional2->setConditionType(\PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS)
-        ->setOperatorType(\PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_LESSTHAN)
+$conditional2 = new Conditional();
+$conditional2->setConditionType(Conditional::CONDITION_CELLIS)
+        ->setOperatorType(Conditional::OPERATOR_LESSTHAN)
         ->addCondition('0');
-$conditional2->getStyle()->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_RED);
+$conditional2->getStyle()->getFont()->getColor()->setARGB(Color::COLOR_RED);
 $conditional2->getStyle()->getFont()->setItalic(true);
-$conditional2->getStyle()->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
+$conditional2->getStyle()->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
 
-$conditional3 = new \PhpOffice\PhpSpreadsheet\Style\Conditional();
-$conditional3->setConditionType(\PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS)
-        ->setOperatorType(\PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_GREATERTHANOREQUAL)
+$conditional3 = new Conditional();
+$conditional3->setConditionType(Conditional::CONDITION_CELLIS)
+        ->setOperatorType(Conditional::OPERATOR_GREATERTHANOREQUAL)
         ->addCondition('0');
-$conditional3->getStyle()->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_GREEN);
+$conditional3->getStyle()->getFont()->getColor()->setARGB(Color::COLOR_GREEN);
 $conditional3->getStyle()->getFont()->setItalic(true);
-$conditional3->getStyle()->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
+$conditional3->getStyle()->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
 
 $conditionalStyles = $spreadsheet->getActiveSheet()->getStyle('B2')->getConditionalStyles();
 array_push($conditionalStyles, $conditional1);
@@ -98,8 +104,8 @@ $spreadsheet->getActiveSheet()->getHeaderFooter()->setOddFooter('&L&B' . $spread
 
 // Set page orientation and size
 $helper->log('Set page orientation and size');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_PORTRAIT);
-$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_PORTRAIT);
+$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(PageSetup::PAPERSIZE_A4);
 
 // Rename worksheet
 $helper->log('Rename worksheet');
diff --git a/samples/08_Conditional_formatting_2.php b/samples/08_Conditional_formatting_2.php
index 87bd2851..07d2361d 100644
--- a/samples/08_Conditional_formatting_2.php
+++ b/samples/08_Conditional_formatting_2.php
@@ -1,10 +1,15 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Conditional;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -32,22 +37,22 @@ $spreadsheet->getActiveSheet()
 $spreadsheet->getActiveSheet()->getStyle('A1:A8')
         ->getNumberFormat()
         ->setFormatCode(
-            \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_PERCENTAGE_00
+            NumberFormat::FORMAT_PERCENTAGE_00
         );
 
 // Add conditional formatting
 $helper->log('Add conditional formatting');
-$conditional1 = new \PhpOffice\PhpSpreadsheet\Style\Conditional();
-$conditional1->setConditionType(\PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS)
-        ->setOperatorType(\PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_LESSTHAN)
+$conditional1 = new Conditional();
+$conditional1->setConditionType(Conditional::CONDITION_CELLIS)
+        ->setOperatorType(Conditional::OPERATOR_LESSTHAN)
         ->addCondition('0');
-$conditional1->getStyle()->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_RED);
+$conditional1->getStyle()->getFont()->getColor()->setARGB(Color::COLOR_RED);
 
-$conditional3 = new \PhpOffice\PhpSpreadsheet\Style\Conditional();
-$conditional3->setConditionType(\PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS)
-        ->setOperatorType(\PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_GREATERTHANOREQUAL)
+$conditional3 = new Conditional();
+$conditional3->setConditionType(Conditional::CONDITION_CELLIS)
+        ->setOperatorType(Conditional::OPERATOR_GREATERTHANOREQUAL)
         ->addCondition('1');
-$conditional3->getStyle()->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_GREEN);
+$conditional3->getStyle()->getFont()->getColor()->setARGB(Color::COLOR_GREEN);
 
 $conditionalStyles = $spreadsheet->getActiveSheet()->getStyle('A1')->getConditionalStyles();
 array_push($conditionalStyles, $conditional1);
diff --git a/samples/09_Pagebreaks.php b/samples/09_Pagebreaks.php
index 9b91d2f0..c4cf33af 100644
--- a/samples/09_Pagebreaks.php
+++ b/samples/09_Pagebreaks.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -36,7 +39,7 @@ for ($i = 2; $i <= 50; ++$i) {
     // Add page breaks every 10 rows
     if ($i % 10 == 0) {
         // Add a page break
-        $spreadsheet->getActiveSheet()->setBreak('A' . $i, \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_ROW);
+        $spreadsheet->getActiveSheet()->setBreak('A' . $i, Worksheet::BREAK_ROW);
     }
 }
 
diff --git a/samples/10_Autofilter.php b/samples/10_Autofilter.php
index 45955a8c..7058e6a5 100644
--- a/samples/10_Autofilter.php
+++ b/samples/10_Autofilter.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/10_Autofilter_selection_1.php b/samples/10_Autofilter_selection_1.php
index 6f74f483..1b34b019 100644
--- a/samples/10_Autofilter_selection_1.php
+++ b/samples/10_Autofilter_selection_1.php
@@ -1,10 +1,16 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -48,7 +54,7 @@ foreach ($years as $year) {
         foreach ($countries as $country) {
             $endDays = date('t', mktime(0, 0, 0, $period, 1, $year));
             for ($i = 1; $i <= $endDays; ++$i) {
-                $eDate = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                $eDate = Date::formattedPHPToExcel(
                     $year,
                     $period,
                     $i
@@ -86,8 +92,8 @@ $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getFont()->setBold(true);
 $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getAlignment()->setWrapText(true);
 $spreadsheet->getActiveSheet()->getColumnDimension('C')->setWidth(12.5);
 $spreadsheet->getActiveSheet()->getColumnDimension('D')->setWidth(10.5);
-$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD2);
-$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
+$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_YYYYMMDD2);
+$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
 $spreadsheet->getActiveSheet()->getColumnDimension('F')->setWidth(14);
 $spreadsheet->getActiveSheet()->freezePane('A2');
 
@@ -104,45 +110,45 @@ $helper->log('Set active filters');
 // Filter the Country column on a filter value of countries beginning with the letter U (or Japan)
 //     We use * as a wildcard, so specify as U* and using a wildcard requires customFilter
 $autoFilter->getColumn('C')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             'u*'
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 $autoFilter->getColumn('C')
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             'japan'
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 // Filter the Date column on a filter value of the first day of every period of the current year
 //	We us a dateGroup ruletype for this, although it is still a standard filter
 foreach ($periods as $period) {
     $endDate = date('t', mktime(0, 0, 0, $period, 1, $currentYear));
 
     $autoFilter->getColumn('D')
-            ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER)
+            ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
             ->createRule()
             ->setRule(
-                \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+                Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
                 [
                 'year' => $currentYear,
                 'month' => $period,
                 'day' => $endDate,
                     ]
             )
-            ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP);
+            ->setRuleType(Rule::AUTOFILTER_RULETYPE_DATEGROUP);
 }
 // Display only sales values that are blank
 //     Standard filter, operator equals, and value of NULL
 $autoFilter->getColumn('E')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             ''
         );
 
diff --git a/samples/10_Autofilter_selection_2.php b/samples/10_Autofilter_selection_2.php
index 1802d0ea..9bfb254a 100644
--- a/samples/10_Autofilter_selection_2.php
+++ b/samples/10_Autofilter_selection_2.php
@@ -1,10 +1,16 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -48,7 +54,7 @@ foreach ($years as $year) {
         foreach ($countries as $country) {
             $endDays = date('t', mktime(0, 0, 0, $period, 1, $year));
             for ($i = 1; $i <= $endDays; ++$i) {
-                $eDate = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                $eDate = Date::formattedPHPToExcel(
                     $year,
                     $period,
                     $i
@@ -86,8 +92,8 @@ $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getFont()->setBold(true);
 $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getAlignment()->setWrapText(true);
 $spreadsheet->getActiveSheet()->getColumnDimension('C')->setWidth(12.5);
 $spreadsheet->getActiveSheet()->getColumnDimension('D')->setWidth(10.5);
-$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD2);
-$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
+$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_YYYYMMDD2);
+$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
 $spreadsheet->getActiveSheet()->getColumnDimension('F')->setWidth(14);
 $spreadsheet->getActiveSheet()->freezePane('A2');
 
@@ -104,39 +110,39 @@ $helper->log('Set active filters');
 // Filter the Country column on a filter value of Germany
 //	As it's just a simple value filter, we can use FILTERTYPE_FILTER
 $autoFilter->getColumn('C')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             'Germany'
         );
 // Filter the Date column on a filter value of the year to date
 $autoFilter->getColumn('D')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             null,
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_YEARTODATE
+            Rule::AUTOFILTER_RULETYPE_DYNAMIC_YEARTODATE
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMICFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_DYNAMICFILTER);
 // Display only sales values that are between 400 and 600
 $autoFilter->getColumn('E')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_GREATERTHANOREQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_GREATERTHANOREQUAL,
             400
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 $autoFilter->getColumn('E')
-        ->setJoin(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND)
+        ->setJoin(Column::AUTOFILTER_COLUMN_JOIN_AND)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_LESSTHANOREQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_LESSTHANOREQUAL,
             600
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 
 // Save
 $helper->write($spreadsheet, __FILE__);
diff --git a/samples/10_Autofilter_selection_display.php b/samples/10_Autofilter_selection_display.php
index 0f431e66..2be654d3 100644
--- a/samples/10_Autofilter_selection_display.php
+++ b/samples/10_Autofilter_selection_display.php
@@ -1,10 +1,16 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -48,7 +54,7 @@ foreach ($years as $year) {
         foreach ($countries as $country) {
             $endDays = date('t', mktime(0, 0, 0, $period, 1, $year));
             for ($i = 1; $i <= $endDays; ++$i) {
-                $eDate = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                $eDate = Date::formattedPHPToExcel(
                     $year,
                     $period,
                     $i
@@ -86,8 +92,8 @@ $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getFont()->setBold(true);
 $spreadsheet->getActiveSheet()->getStyle('A1:F1')->getAlignment()->setWrapText(true);
 $spreadsheet->getActiveSheet()->getColumnDimension('C')->setWidth(12.5);
 $spreadsheet->getActiveSheet()->getColumnDimension('D')->setWidth(10.5);
-$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD2);
-$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
+$spreadsheet->getActiveSheet()->getStyle('D2:D' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_YYYYMMDD2);
+$spreadsheet->getActiveSheet()->getStyle('E2:F' . $row)->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
 $spreadsheet->getActiveSheet()->getColumnDimension('F')->setWidth(14);
 $spreadsheet->getActiveSheet()->freezePane('A2');
 
@@ -104,45 +110,45 @@ $helper->log('Set active filters');
 // Filter the Country column on a filter value of countries beginning with the letter U (or Japan)
 //     We use * as a wildcard, so specify as U* and using a wildcard requires customFilter
 $autoFilter->getColumn('C')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_CUSTOMFILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             'u*'
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 $autoFilter->getColumn('C')
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             'japan'
         )
-        ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
+        ->setRuleType(Rule::AUTOFILTER_RULETYPE_CUSTOMFILTER);
 // Filter the Date column on a filter value of the first day of every period of the current year
 //	We us a dateGroup ruletype for this, although it is still a standard filter
 foreach ($periods as $period) {
     $endDate = date('t', mktime(0, 0, 0, $period, 1, $currentYear));
 
     $autoFilter->getColumn('D')
-            ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER)
+            ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
             ->createRule()
             ->setRule(
-                \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+                Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
                 [
                 'year' => $currentYear,
                 'month' => $period,
                 'day' => $endDate,
                     ]
             )
-            ->setRuleType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP);
+            ->setRuleType(Rule::AUTOFILTER_RULETYPE_DATEGROUP);
 }
 // Display only sales values that are blank
 //     Standard filter, operator equals, and value of NULL
 $autoFilter->getColumn('E')
-        ->setFilterType(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER)
+        ->setFilterType(Column::AUTOFILTER_FILTERTYPE_FILTER)
         ->createRule()
         ->setRule(
-            \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
+            Rule::AUTOFILTER_COLUMN_RULE_EQUAL,
             ''
         );
 
diff --git a/samples/11_Documentsecurity.php b/samples/11_Documentsecurity.php
index 2224808a..0298e7ee 100644
--- a/samples/11_Documentsecurity.php
+++ b/samples/11_Documentsecurity.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/12_CellProtection.php b/samples/12_CellProtection.php
index 4ef97b01..a84bb8a5 100644
--- a/samples/12_CellProtection.php
+++ b/samples/12_CellProtection.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -37,7 +40,7 @@ $spreadsheet->getActiveSheet()->getProtection()->setSheet(true);
 $spreadsheet->getActiveSheet()
         ->getStyle('A2:B2')
         ->getProtection()->setLocked(
-            \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED
+            Protection::PROTECTION_UNPROTECTED
         );
 
 // Save
diff --git a/samples/13_Calculation.php b/samples/13_Calculation.php
index d620a6f2..e143e9ab 100644
--- a/samples/13_Calculation.php
+++ b/samples/13_Calculation.php
@@ -1,17 +1,20 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 mt_srand(1234567890);
 
 require __DIR__ . '/Header.php';
 
 // List functions
 $helper->log('List implemented functions');
-$calc = \PhpOffice\PhpSpreadsheet\Calculation::getInstance();
+$calc = Calculation::getInstance();
 print_r($calc->getImplementedFunctionNames());
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Add some data, we will use some formulas here
 $helper->log('Add some data and formulas');
diff --git a/samples/13_CalculationCyclicFormulae.php b/samples/13_CalculationCyclicFormulae.php
index ea1be404..968c467c 100644
--- a/samples/13_CalculationCyclicFormulae.php
+++ b/samples/13_CalculationCyclicFormulae.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Add some data, we will use some formulas here
 $helper->log('Add some data and formulas');
@@ -13,7 +16,7 @@ $spreadsheet->getActiveSheet()->setCellValue('A1', '=B1')
         ->setCellValue('B1', '=A1+1')
         ->setCellValue('B2', '=A2');
 
-\PhpOffice\PhpSpreadsheet\Calculation::getInstance($spreadsheet)->cyclicFormulaCount = 100;
+Calculation::getInstance($spreadsheet)->cyclicFormulaCount = 100;
 
 // Calculated data
 $helper->log('Calculated data');
diff --git a/samples/14_Xls.php b/samples/14_Xls.php
index 86d125b9..03a38d28 100644
--- a/samples/14_Xls.php
+++ b/samples/14_Xls.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
 $filename = $helper->getFilename(__FILE__, 'xls');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xls');
+$writer = IOFactory::createWriter($spreadsheet, 'Xls');
 
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/15_Datavalidation.php b/samples/15_Datavalidation.php
index bd7299d6..416a102a 100644
--- a/samples/15_Datavalidation.php
+++ b/samples/15_Datavalidation.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -35,8 +38,8 @@ $spreadsheet->getActiveSheet()->setCellValue('A1', 'Cell B3 and B5 contain data
 // Set data validation
 $helper->log('Set data validation');
 $validation = $spreadsheet->getActiveSheet()->getCell('B3')->getDataValidation();
-$validation->setType(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_WHOLE);
-$validation->setErrorStyle(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_STOP);
+$validation->setType(DataValidation::TYPE_WHOLE);
+$validation->setErrorStyle(DataValidation::STYLE_STOP);
 $validation->setAllowBlank(true);
 $validation->setShowInputMessage(true);
 $validation->setShowErrorMessage(true);
@@ -48,8 +51,8 @@ $validation->setFormula1(10);
 $validation->setFormula2(20);
 
 $validation = $spreadsheet->getActiveSheet()->getCell('B5')->getDataValidation();
-$validation->setType(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST);
-$validation->setErrorStyle(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION);
+$validation->setType(DataValidation::TYPE_LIST);
+$validation->setErrorStyle(DataValidation::STYLE_INFORMATION);
 $validation->setAllowBlank(false);
 $validation->setShowInputMessage(true);
 $validation->setShowErrorMessage(true);
@@ -61,8 +64,8 @@ $validation->setPrompt('Please pick a value from the drop-down list.');
 $validation->setFormula1('"Item A,Item B,Item C"'); // Make sure to put the list items between " and " if your list is simply a comma-separated list of values !!!
 
 $validation = $spreadsheet->getActiveSheet()->getCell('B7')->getDataValidation();
-$validation->setType(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST);
-$validation->setErrorStyle(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION);
+$validation->setType(DataValidation::TYPE_LIST);
+$validation->setErrorStyle(DataValidation::STYLE_INFORMATION);
 $validation->setAllowBlank(false);
 $validation->setShowInputMessage(true);
 $validation->setShowErrorMessage(true);
diff --git a/samples/16_Csv.php b/samples/16_Csv.php
index 63cbd53e..0c1db51d 100644
--- a/samples/16_Csv.php
+++ b/samples/16_Csv.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
 $helper->log('Write to CSV format');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Csv')->setDelimiter(',')
+$writer = IOFactory::createWriter($spreadsheet, 'Csv')->setDelimiter(',')
         ->setEnclosure('"')
         ->setSheetIndex(0);
 
@@ -15,7 +17,7 @@ $helper->logWrite($writer, $filename, $callStartTime);
 
 $helper->log('Read from CSV format');
 
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Csv')->setDelimiter(',')
+$reader = IOFactory::createReader('Csv')->setDelimiter(',')
         ->setEnclosure('"')
         ->setSheetIndex(0);
 
@@ -28,7 +30,7 @@ $helper->write($spreadsheetFromCSV, __FILE__, ['Xlsx']);
 
 // Write CSV
 $filenameCSV = $helper->getFilename(__FILE__, 'csv');
-$writerCSV = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheetFromCSV, 'Csv');
+$writerCSV = IOFactory::createWriter($spreadsheetFromCSV, 'Csv');
 $writerCSV->setExcelCompatibility(true);
 
 $callStartTime = microtime(true);
diff --git a/samples/17_Html.php b/samples/17_Html.php
index d3dfd5b0..9ea9f0bd 100644
--- a/samples/17_Html.php
+++ b/samples/17_Html.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
 $filename = $helper->getFilename(__FILE__, 'html');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Html');
+$writer = IOFactory::createWriter($spreadsheet, 'Html');
 
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/18_Extendedcalculation.php b/samples/18_Extendedcalculation.php
index b7d45b33..e459e9d3 100644
--- a/samples/18_Extendedcalculation.php
+++ b/samples/18_Extendedcalculation.php
@@ -1,16 +1,18 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
 // List functions
 $helper->log('List implemented functions');
-$calc = \PhpOffice\PhpSpreadsheet\Calculation::getInstance();
+$calc = Calculation::getInstance();
 print_r($calc->getImplementedFunctionNames());
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Add some data, we will use some formulas here
 $helper->log('Add some data');
diff --git a/samples/19_Namedrange.php b/samples/19_Namedrange.php
index ea39a335..53c25660 100644
--- a/samples/19_Namedrange.php
+++ b/samples/19_Namedrange.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\NamedRange;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -28,8 +31,8 @@ $spreadsheet->getActiveSheet()->setCellValue('A1', 'Firstname:')
 
 // Define named ranges
 $helper->log('Define named ranges');
-$spreadsheet->addNamedRange(new \PhpOffice\PhpSpreadsheet\NamedRange('PersonName', $spreadsheet->getActiveSheet(), 'B1'));
-$spreadsheet->addNamedRange(new \PhpOffice\PhpSpreadsheet\NamedRange('PersonLN', $spreadsheet->getActiveSheet(), 'B2'));
+$spreadsheet->addNamedRange(new NamedRange('PersonName', $spreadsheet->getActiveSheet(), 'B1'));
+$spreadsheet->addNamedRange(new NamedRange('PersonLN', $spreadsheet->getActiveSheet(), 'B2'));
 
 // Rename named ranges
 $helper->log('Rename named ranges');
diff --git a/samples/20_Read_Excel2003XML.php b/samples/20_Read_Excel2003XML.php
index e6c1a797..6e2f464d 100644
--- a/samples/20_Read_Excel2003XML.php
+++ b/samples/20_Read_Excel2003XML.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $filename = __DIR__ . '/templates/Excel2003XMLTest.xml';
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Xml', $filename, $callStartTime);
 
 // Save
diff --git a/samples/20_Read_Gnumeric.php b/samples/20_Read_Gnumeric.php
index d390dc14..d2c598c4 100644
--- a/samples/20_Read_Gnumeric.php
+++ b/samples/20_Read_Gnumeric.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $filename = __DIR__ . '/templates/GnumericTest.gnumeric';
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Gnumeric', $filename, $callStartTime);
 
 // Save
diff --git a/samples/20_Read_Ods.php b/samples/20_Read_Ods.php
index 37f7d4f7..10a8275c 100644
--- a/samples/20_Read_Ods.php
+++ b/samples/20_Read_Ods.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $filename = __DIR__ . '/templates/OOCalcTest.ods';
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Ods', $filename, $callStartTime);
 
 // Save
diff --git a/samples/20_Read_Sylk.php b/samples/20_Read_Sylk.php
index b3baa5a5..c07c9647 100644
--- a/samples/20_Read_Sylk.php
+++ b/samples/20_Read_Sylk.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $filename = __DIR__ . '/templates/SylkTest.slk';
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Slk', $filename, $callStartTime);
 
 // Save
diff --git a/samples/20_Read_Xls.php b/samples/20_Read_Xls.php
index ef8b1eda..542f96a2 100644
--- a/samples/20_Read_Xls.php
+++ b/samples/20_Read_Xls.php
@@ -1,19 +1,21 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
 // Write temporary file
 $filename = $helper->getTemporaryFilename('xls');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xls');
+$writer = IOFactory::createWriter($spreadsheet, 'Xls');
 $callStartTime = microtime(true);
 $writer->save($filename);
 $helper->logWrite($writer, $filename, $callStartTime);
 
 // Read Xls file
 $callStartTime = microtime(true);
-$spreadsheet = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheet = IOFactory::load($filename);
 $helper->logRead('Xls', $filename, $callStartTime);
 
 // Save
diff --git a/samples/21_Pdf_Domdf.php b/samples/21_Pdf_Domdf.php
index bc891d6f..f13ca72c 100644
--- a/samples/21_Pdf_Domdf.php
+++ b/samples/21_Pdf_Domdf.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
@@ -7,11 +10,11 @@ $helper->log('Hide grid lines');
 $spreadsheet->getActiveSheet()->setShowGridLines(false);
 
 $helper->log('Set orientation to landscape');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
 
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_DOMPDF;
+$rendererName = Settings::PDF_RENDERER_DOMPDF;
 $helper->log("Write to PDF format using {$rendererName}");
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 
 // Save
 $helper->write($spreadsheet, __FILE__, ['Pdf']);
diff --git a/samples/21_Pdf_TCPDF.php b/samples/21_Pdf_TCPDF.php
index 980069fc..1bf75c84 100644
--- a/samples/21_Pdf_TCPDF.php
+++ b/samples/21_Pdf_TCPDF.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
@@ -7,11 +10,11 @@ $helper->log('Hide grid lines');
 $spreadsheet->getActiveSheet()->setShowGridLines(false);
 
 $helper->log('Set orientation to landscape');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
 
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_TCPDF;
+$rendererName = Settings::PDF_RENDERER_TCPDF;
 $helper->log("Write to PDF format using {$rendererName}");
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 
 // Save
 $helper->write($spreadsheet, __FILE__, ['Pdf']);
diff --git a/samples/21_Pdf_mPDF.php b/samples/21_Pdf_mPDF.php
index b5327a61..8e46f838 100644
--- a/samples/21_Pdf_mPDF.php
+++ b/samples/21_Pdf_mPDF.php
@@ -1,5 +1,8 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 require __DIR__ . '/Header.php';
 $spreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 
@@ -7,11 +10,11 @@ $helper->log('Hide grid lines');
 $spreadsheet->getActiveSheet()->setShowGridLines(false);
 
 $helper->log('Set orientation to landscape');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
 
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_MPDF;
+$rendererName = Settings::PDF_RENDERER_MPDF;
 $helper->log("Write to PDF format using {$rendererName}");
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 
 // Save
 $helper->write($spreadsheet, __FILE__, ['Pdf']);
diff --git a/samples/22_Heavily_formatted.php b/samples/22_Heavily_formatted.php
index 541f3149..ea4cd804 100644
--- a/samples/22_Heavily_formatted.php
+++ b/samples/22_Heavily_formatted.php
@@ -1,10 +1,14 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -22,19 +26,19 @@ $spreadsheet->setActiveSheetIndex(0);
 
 $spreadsheet->getActiveSheet()->getStyle('A1:T100')->applyFromArray(
     ['fill' => [
-                'type' => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID,
+                'type' => Fill::FILL_SOLID,
                 'color' => ['argb' => 'FFCCFFCC'],
             ],
             'borders' => [
-                'bottom' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN],
-                'right' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM],
+                'bottom' => ['style' => Border::BORDER_THIN],
+                'right' => ['style' => Border::BORDER_MEDIUM],
             ],
         ]
 );
 
 $spreadsheet->getActiveSheet()->getStyle('C5:R95')->applyFromArray(
     ['fill' => [
-                'type' => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID,
+                'type' => Fill::FILL_SOLID,
                 'color' => ['argb' => 'FFFFFF00'],
             ],
         ]
diff --git a/samples/23_Sharedstyles.php b/samples/23_Sharedstyles.php
index 48ffb1ad..74e3d8d6 100644
--- a/samples/23_Sharedstyles.php
+++ b/samples/23_Sharedstyles.php
@@ -1,10 +1,15 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -20,29 +25,29 @@ $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
 $helper->log('Add some data');
 $spreadsheet->setActiveSheetIndex(0);
 
-$sharedStyle1 = new \PhpOffice\PhpSpreadsheet\Style();
-$sharedStyle2 = new \PhpOffice\PhpSpreadsheet\Style();
+$sharedStyle1 = new Style();
+$sharedStyle2 = new Style();
 
 $sharedStyle1->applyFromArray(
     ['fill' => [
-                'type' => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID,
+                'type' => Fill::FILL_SOLID,
                 'color' => ['argb' => 'FFCCFFCC'],
             ],
             'borders' => [
-                'bottom' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN],
-                'right' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM],
+                'bottom' => ['style' => Border::BORDER_THIN],
+                'right' => ['style' => Border::BORDER_MEDIUM],
             ],
         ]
 );
 
 $sharedStyle2->applyFromArray(
     ['fill' => [
-                'type' => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID,
+                'type' => Fill::FILL_SOLID,
                 'color' => ['argb' => 'FFFFFF00'],
             ],
             'borders' => [
-                'bottom' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN],
-                'right' => ['style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM],
+                'bottom' => ['style' => Border::BORDER_THIN],
+                'right' => ['style' => Border::BORDER_MEDIUM],
             ],
         ]
 );
diff --git a/samples/24_Readfilter.php b/samples/24_Readfilter.php
index 17912705..f5258604 100644
--- a/samples/24_Readfilter.php
+++ b/samples/24_Readfilter.php
@@ -2,17 +2,20 @@
 
 namespace PhpOffice\PhpSpreadsheet;
 
+use PhpOffice\PhpSpreadsheet\Reader\IReadFilter;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
+
 require __DIR__ . '/Header.php';
 
 // Write temporary file
 $largeSpreadsheet = require __DIR__ . '/templates/largeSpreadsheet.php';
-$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($largeSpreadsheet);
+$writer = new Xlsx($largeSpreadsheet);
 $filename = $helper->getTemporaryFilename();
 $callStartTime = microtime(true);
 $writer->save($filename);
 $helper->logWrite($writer, $filename, $callStartTime);
 
-class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
+class MyReadFilter implements IReadFilter
 {
     public function readCell($column, $row, $worksheetName = '')
     {
@@ -26,7 +29,7 @@ class MyReadFilter implements \PhpOffice\PhpSpreadsheet\Reader\IReadFilter
 }
 
 $helper->log('Load from Xlsx file');
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xlsx');
+$reader = IOFactory::createReader('Xlsx');
 $reader->setReadFilter(new MyReadFilter());
 $callStartTime = microtime(true);
 $spreadsheet = $reader->load($filename);
diff --git a/samples/25_In_memory_image.php b/samples/25_In_memory_image.php
index aef166f1..5756bd3e 100644
--- a/samples/25_In_memory_image.php
+++ b/samples/25_In_memory_image.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -24,12 +27,12 @@ imagestring($gdImage, 1, 5, 5, 'Created with PhpSpreadsheet', $textColor);
 
 // Add a drawing to the worksheet
 $helper->log('Add a drawing to the worksheet');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing();
+$drawing = new MemoryDrawing();
 $drawing->setName('Sample image');
 $drawing->setDescription('Sample image');
 $drawing->setImageResource($gdImage);
-$drawing->setRenderingFunction(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_JPEG);
-$drawing->setMimeType(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::MIMETYPE_DEFAULT);
+$drawing->setRenderingFunction(MemoryDrawing::RENDERING_JPEG);
+$drawing->setMimeType(MemoryDrawing::MIMETYPE_DEFAULT);
 $drawing->setHeight(36);
 $drawing->setWorksheet($spreadsheet->getActiveSheet());
 
diff --git a/samples/26_Utf8.php b/samples/26_Utf8.php
index 105b0f94..790640a0 100644
--- a/samples/26_Utf8.php
+++ b/samples/26_Utf8.php
@@ -1,16 +1,19 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Settings;
+
 require __DIR__ . '/Header.php';
 
 //	Change these values to select the PDF Rendering library that you wish to use
 //		and its directory location on your server
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_TCPDF;
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_MPDF;
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_DOMPDF;
+$rendererName = Settings::PDF_RENDERER_DOMPDF;
 
 // Read from Xlsx (.xlsx) template
 $helper->log('Load Xlsx template file');
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xlsx');
+$reader = IOFactory::createReader('Xlsx');
 $spreadsheet = $reader->load(__DIR__ . '/templates/26template.xlsx');
 
 /* at this point, we could do some manipulations with the template, but we skip this step */
@@ -18,7 +21,7 @@ $helper->write($spreadsheet, __FILE__, ['Xlsx', 'Xls', 'Html']);
 
 // Export to PDF (.pdf)
 $helper->log('Write to PDF format');
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 $helper->write($spreadsheet, __FILE__, ['Pdf']);
 
 // Remove first two rows with field headers before exporting to CSV
@@ -28,7 +31,7 @@ $worksheet->removeRow(1, 2);
 
 // Export to CSV (.csv)
 $helper->log('Write to CSV format');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Csv');
+$writer = IOFactory::createWriter($spreadsheet, 'Csv');
 $filename = $helper->getFilename(__FILE__, 'csv');
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/27_Images_Xls.php b/samples/27_Images_Xls.php
index 8fc7bf2b..4923efe2 100644
--- a/samples/27_Images_Xls.php
+++ b/samples/27_Images_Xls.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 // Read from Xls (.xls) template
 $helper->log('Load Xlsx template file');
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xls');
+$reader = IOFactory::createReader('Xls');
 $spreadsheet = $reader->load(__DIR__ . '/templates/27template.xls');
 
 // Save
diff --git a/samples/28_Iterator.php b/samples/28_Iterator.php
index 95bed125..5dbb49e4 100644
--- a/samples/28_Iterator.php
+++ b/samples/28_Iterator.php
@@ -1,16 +1,19 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
+
 require __DIR__ . '/Header.php';
 
 $sampleSpreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 $filename = $helper->getTemporaryFilename();
-$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($sampleSpreadsheet);
+$writer = new Xlsx($sampleSpreadsheet);
 $callStartTime = microtime(true);
 $writer->save($filename);
 $helper->logWrite($writer, $filename, $callStartTime);
 
 $callStartTime = microtime(true);
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xlsx');
+$reader = IOFactory::createReader('Xlsx');
 $spreadsheet = $reader->load($filename);
 $helper->logRead('Xlsx', $filename, $callStartTime);
 $helper->log('Iterate worksheets');
diff --git a/samples/29_Advanced_value_binder.php b/samples/29_Advanced_value_binder.php
index 260a612b..7f22c8f0 100644
--- a/samples/29_Advanced_value_binder.php
+++ b/samples/29_Advanced_value_binder.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
@@ -9,11 +11,11 @@ date_default_timezone_set('UTC');
 
 // Set value binder
 $helper->log('Set value binder');
-\PhpOffice\PhpSpreadsheet\Cell::setValueBinder(new \PhpOffice\PhpSpreadsheet\Cell\AdvancedValueBinder());
+Cell::setValueBinder(new Cell\AdvancedValueBinder());
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/30_Template.php b/samples/30_Template.php
index ed6f588e..4c6d867b 100644
--- a/samples/30_Template.php
+++ b/samples/30_Template.php
@@ -1,9 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+
 require __DIR__ . '/Header.php';
 
 $helper->log('Load from Xls template');
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xls');
+$reader = IOFactory::createReader('Xls');
 $spreadsheet = $reader->load(__DIR__ . '/templates/30template.xls');
 
 $helper->log('Add new data to the template');
@@ -21,7 +24,7 @@ $data = [['title' => 'Excel for dummies',
     ],
 ];
 
-$spreadsheet->getActiveSheet()->setCellValue('D1', \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(time()));
+$spreadsheet->getActiveSheet()->setCellValue('D1', Date::PHPToExcel(time()));
 
 $baseRow = 5;
 foreach ($data as $r => $dataRow) {
diff --git a/samples/31_Document_properties_write.php b/samples/31_Document_properties_write.php
index 76aeaa62..15936ffa 100644
--- a/samples/31_Document_properties_write.php
+++ b/samples/31_Document_properties_write.php
@@ -1,11 +1,14 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Document\Properties;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $inputFileType = 'Xlsx';
 $inputFileName = __DIR__ . '/templates/31docproperties.xlsx';
 
-$spreadsheetReader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$spreadsheetReader = IOFactory::createReader($inputFileType);
 $callStartTime = microtime(true);
 $spreadsheet = $spreadsheetReader->load($inputFileName);
 $helper->logRead($inputFileType, $inputFileName, $callStartTime);
@@ -18,7 +21,7 @@ $spreadsheet->getProperties()->setTitle('Office 2007 XLSX Test Document')
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $callStartTime = microtime(true);
 $writer->save($filename);
 $helper->logWrite($writer, $filename, $callStartTime);
@@ -28,7 +31,7 @@ $helper->logEndingNotes();
 
 // Reread File
 $helper->log('Reread Xlsx file');
-$spreadsheetRead = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheetRead = IOFactory::load($filename);
 
 // Set properties
 $helper->log('Get properties');
@@ -53,9 +56,9 @@ $customProperties = $spreadsheet->getProperties()->getCustomProperties();
 foreach ($customProperties as $customProperty) {
     $propertyValue = $spreadsheet->getProperties()->getCustomPropertyValue($customProperty);
     $propertyType = $spreadsheet->getProperties()->getCustomPropertyType($customProperty);
-    if ($propertyType == \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_DATE) {
+    if ($propertyType == Properties::PROPERTY_TYPE_DATE) {
         $formattedValue = date('d-M-Y H:i:s', $propertyValue);
-    } elseif ($propertyType == \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_BOOLEAN) {
+    } elseif ($propertyType == Properties::PROPERTY_TYPE_BOOLEAN) {
         $formattedValue = $propertyValue ? 'TRUE' : 'FALSE';
     } else {
         $formattedValue = $propertyValue;
diff --git a/samples/31_Document_properties_write_xls.php b/samples/31_Document_properties_write_xls.php
index 38f15354..a427be18 100644
--- a/samples/31_Document_properties_write_xls.php
+++ b/samples/31_Document_properties_write_xls.php
@@ -1,11 +1,14 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Document\Properties;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $inputFileType = 'Xls';
 $inputFileName = __DIR__ . '/templates/31docproperties.xls';
 
-$spreadsheetReader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$spreadsheetReader = IOFactory::createReader($inputFileType);
 $callStartTime = microtime(true);
 $spreadsheet = $spreadsheetReader->load($inputFileName);
 $helper->logRead($inputFileType, $inputFileName, $callStartTime);
@@ -18,7 +21,7 @@ $spreadsheet->getProperties()->setTitle('Office 95 XLS Test Document')
 
 // Save Excel 95 file
 $filename = $helper->getFilename(__FILE__, 'xls');
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xls');
+$writer = IOFactory::createWriter($spreadsheet, 'Xls');
 $callStartTime = microtime(true);
 $writer->save($filename);
 $helper->logWrite($writer, $filename, $callStartTime);
@@ -28,7 +31,7 @@ $helper->logEndingNotes();
 
 // Reread File
 $helper->log('Reread Xls file');
-$spreadsheetRead = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename);
+$spreadsheetRead = IOFactory::load($filename);
 
 // Set properties
 $helper->log('Get properties');
@@ -53,9 +56,9 @@ $customProperties = $spreadsheet->getProperties()->getCustomProperties();
 foreach ($customProperties as $customProperty) {
     $propertyValue = $spreadsheet->getProperties()->getCustomPropertyValue($customProperty);
     $propertyType = $spreadsheet->getProperties()->getCustomPropertyType($customProperty);
-    if ($propertyType == \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_DATE) {
+    if ($propertyType == Properties::PROPERTY_TYPE_DATE) {
         $formattedValue = date('d-M-Y H:i:s', $propertyValue);
-    } elseif ($propertyType == \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_BOOLEAN) {
+    } elseif ($propertyType == Properties::PROPERTY_TYPE_BOOLEAN) {
         $formattedValue = $propertyValue ? 'TRUE' : 'FALSE';
     } else {
         $formattedValue = $propertyValue;
diff --git a/samples/32_Chart_read_write.php b/samples/32_Chart_read_write.php
index 2ae0b8ae..6668280c 100644
--- a/samples/32_Chart_read_write.php
+++ b/samples/32_Chart_read_write.php
@@ -1,5 +1,7 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $inputFileType = 'Xlsx';
@@ -20,7 +22,7 @@ foreach ($inputFileNames as $inputFileName) {
         $helper->log('File ' . $inputFileNameShort . ' does not exist');
         continue;
     }
-    $reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+    $reader = IOFactory::createReader($inputFileType);
     $reader->setIncludeCharts(true);
     $callStartTime = microtime(true);
     $spreadsheet = $reader->load($inputFileName);
@@ -69,7 +71,7 @@ foreach ($inputFileNames as $inputFileName) {
     }
 
     $outputFileName = $helper->getFilename($inputFileName);
-    $writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+    $writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
     $writer->setIncludeCharts(true);
     $callStartTime = microtime(true);
     $writer->save($outputFileName);
diff --git a/samples/32_Chart_read_write_HTML.php b/samples/32_Chart_read_write_HTML.php
index aa697efd..ac2d1e1b 100644
--- a/samples/32_Chart_read_write_HTML.php
+++ b/samples/32_Chart_read_write_HTML.php
@@ -1,14 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Settings;
+
 require __DIR__ . '/Header.php';
 
 //	Change these values to select the Rendering library that you wish to use
 //		and its directory location on your server
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::CHART_RENDERER_JPGRAPH;
+$rendererName = Settings::CHART_RENDERER_JPGRAPH;
 $rendererLibrary = 'jpgraph3.5.0b1/src/';
 $rendererLibraryPath = '/php/libraries/Charts/' . $rendererLibrary;
 
-if (!\PhpOffice\PhpSpreadsheet\Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
+if (!Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
     $helper->log('NOTICE: Please set the $rendererName and $rendererLibraryPath values at the top of this script as appropriate for your directory structure');
 
     return;
@@ -35,7 +38,7 @@ foreach ($inputFileNames as $inputFileName) {
 
     $helper->log("Load Test from $inputFileType file " . $inputFileNameShort);
 
-    $reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+    $reader = IOFactory::createReader($inputFileType);
     $reader->setIncludeCharts(true);
     $spreadsheet = $reader->load($inputFileName);
 
@@ -83,7 +86,7 @@ foreach ($inputFileNames as $inputFileName) {
 
     // Save
     $filename = $helper->getFilename($inputFileName);
-    $writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Html');
+    $writer = IOFactory::createWriter($spreadsheet, 'Html');
     $writer->setIncludeCharts(true);
     $callStartTime = microtime(true);
     $writer->save($filename);
diff --git a/samples/32_Chart_read_write_PDF.php b/samples/32_Chart_read_write_PDF.php
index d41f6728..ffd4ba40 100644
--- a/samples/32_Chart_read_write_PDF.php
+++ b/samples/32_Chart_read_write_PDF.php
@@ -1,22 +1,25 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Settings;
+
 require __DIR__ . '/Header.php';
 
 //	Change these values to select the Rendering library that you wish to use
 //		for PDF files, and its directory location on your server
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_TCPDF;
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_MPDF;
+$rendererName = Settings::PDF_RENDERER_MPDF;
 //$rendererName = \PhpOffice\PhpSpreadsheet\Settings::PDF_RENDERER_DOMPDF;
 
-\PhpOffice\PhpSpreadsheet\Settings::setPdfRendererName($rendererName);
+Settings::setPdfRendererName($rendererName);
 
 //	Change these values to select the Rendering library that you wish to use
 //		for Chart images, and its directory location on your server
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::CHART_RENDERER_JPGRAPH;
+$rendererName = Settings::CHART_RENDERER_JPGRAPH;
 $rendererLibrary = 'jpgraph3.5.0b1/src/';
 $rendererLibraryPath = '/php/libraries/Charts/' . $rendererLibrary;
 
-if (!\PhpOffice\PhpSpreadsheet\Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
+if (!Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
     $helper->log('NOTICE: Please set the $rendererName and $rendererLibraryPath values at the top of this script as appropriate for your directory structure');
 
     return;
@@ -43,7 +46,7 @@ foreach ($inputFileNames as $inputFileName) {
 
     $helper->log("Load Test from $inputFileType file " . $inputFileNameShort);
 
-    $reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+    $reader = IOFactory::createReader($inputFileType);
     $reader->setIncludeCharts(true);
     $spreadsheet = $reader->load($inputFileName);
 
@@ -91,7 +94,7 @@ foreach ($inputFileNames as $inputFileName) {
 
     // Save
     $filename = $helper->getFilename($inputFileName);
-    $writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Pdf');
+    $writer = IOFactory::createWriter($spreadsheet, 'Pdf');
     $writer->setIncludeCharts(true);
     $callStartTime = microtime(true);
     $writer->save($filename);
diff --git a/samples/33_Chart_create_area.php b/samples/33_Chart_create_area.php
index 550f8133..76a9f478 100644
--- a/samples/33_Chart_create_area.php
+++ b/samples/33_Chart_create_area.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,9 +31,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -35,7 +43,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -45,15 +53,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_AREACHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_AREACHART, // plotType
+    DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -61,15 +69,15 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_TOPRIGHT, null, false);
+$legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test %age-Stacked Area Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test %age-Stacked Area Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -89,7 +97,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_bar.php b/samples/33_Chart_create_bar.php
index 6889956b..96ac5ef7 100644
--- a/samples/33_Chart_create_bar.php
+++ b/samples/33_Chart_create_bar.php
@@ -1,5 +1,6 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
 
 require __DIR__ . '/Header.php';
 
@@ -7,7 +8,7 @@ $spreadsheet = require __DIR__ . '/templates/chartSpreadsheet.php';
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_bar_stacked.php b/samples/33_Chart_create_bar_stacked.php
index f4bb87bc..af9fb542 100644
--- a/samples/33_Chart_create_bar_stacked.php
+++ b/samples/33_Chart_create_bar_stacked.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,9 +31,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -35,7 +43,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -45,15 +53,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STACKED, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_STACKED, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -61,18 +69,18 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a horizontal bar rather than a vertical column graph
-$series->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_BAR);
+$series->setPlotDirection(DataSeries::DIRECTION_BAR);
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -92,7 +100,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_column.php b/samples/33_Chart_create_column.php
index 1d4023cf..12903ea6 100644
--- a/samples/33_Chart_create_column.php
+++ b/samples/33_Chart_create_column.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,9 +31,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -35,7 +43,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -45,15 +53,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STANDARD, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_STANDARD, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -61,18 +69,18 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a vertical column rather than a horizontal bar graph
-$series->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_COL);
+$series->setPlotDirection(DataSeries::DIRECTION_COL);
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Column Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Column Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -92,7 +100,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_column_2.php b/samples/33_Chart_create_column_2.php
index d459dd5b..8ea8d791 100644
--- a/samples/33_Chart_create_column_2.php
+++ b/samples/33_Chart_create_column_2.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -31,9 +39,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	'Budget'
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	'Forecast'
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$E$1', null, 1), //	'Actual'
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	'Budget'
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	'Forecast'
+    new DataSeriesValues('String', 'Worksheet!$E$1', null, 1), //	'Actual'
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -43,7 +51,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$B$13', null, 12), //	Q1 to Q4 for 2010 to 2012
+    new DataSeriesValues('String', 'Worksheet!$A$2:$B$13', null, 12), //	Q1 to Q4 for 2010 to 2012
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -53,15 +61,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$E$2:$E$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$E$2:$E$13', null, 12),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_CLUSTERED, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_CLUSTERED, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -69,19 +77,19 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a vertical column rather than a horizontal bar graph
-$series->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_COL);
+$series->setPlotDirection(DataSeries::DIRECTION_COL);
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_BOTTOM, null, false);
+$legend = new Legend(Legend::POSITION_BOTTOM, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Grouped Column Chart');
-$xAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Financial Period');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Grouped Column Chart');
+$xAxisLabel = new Title('Financial Period');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -101,7 +109,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_composite.php b/samples/33_Chart_create_composite.php
index 57abd991..d050a3e9 100644
--- a/samples/33_Chart_create_composite.php
+++ b/samples/33_Chart_create_composite.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -31,13 +39,13 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	Temperature
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	Temperature
 ];
 $dataSeriesLabels2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	Rainfall
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	Rainfall
 ];
 $dataSeriesLabels3 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	Humidity
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	Humidity
 ];
 
 //	Set the X-Axis Labels
@@ -48,7 +56,7 @@ $dataSeriesLabels3 = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
 ];
 
 //	Set the Data values for each data series we want to plot
@@ -59,13 +67,13 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$13', null, 12),
 ];
 
 //	Build the dataseries
-$series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_CLUSTERED, // plotGrouping
+$series1 = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_CLUSTERED, // plotGrouping
     range(0, count($dataSeriesValues1) - 1), // plotOrder
     $dataSeriesLabels1, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -73,7 +81,7 @@ $series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a vertical column rather than a horizontal bar graph
-$series1->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_COL);
+$series1->setPlotDirection(DataSeries::DIRECTION_COL);
 
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -83,13 +91,13 @@ $series1->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION
 //		Data values
 //		Data Marker
 $dataSeriesValues2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
 ];
 
 //	Build the dataseries
-$series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_LINECHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STANDARD, // plotGrouping
+$series2 = new DataSeries(
+    DataSeries::TYPE_LINECHART, // plotType
+    DataSeries::GROUPING_STANDARD, // plotGrouping
     range(0, count($dataSeriesValues2) - 1), // plotOrder
     $dataSeriesLabels2, // plotLabel
     null, // plotCategory
@@ -104,13 +112,13 @@ $series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 //		Data values
 //		Data Marker
 $dataSeriesValues3 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
 ];
 
 //	Build the dataseries
-$series3 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_AREACHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STANDARD, // plotGrouping
+$series3 = new DataSeries(
+    DataSeries::TYPE_AREACHART, // plotType
+    DataSeries::GROUPING_STANDARD, // plotGrouping
     range(0, count($dataSeriesValues2) - 1), // plotOrder
     $dataSeriesLabels3, // plotLabel
     null, // plotCategory
@@ -118,14 +126,14 @@ $series3 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series1, $series2, $series3]);
+$plotArea = new PlotArea(null, [$series1, $series2, $series3]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Average Weather Chart for Crete');
+$title = new Title('Average Weather Chart for Crete');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -145,7 +153,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_line.php b/samples/33_Chart_create_line.php
index 556f9530..b2d6e4f3 100644
--- a/samples/33_Chart_create_line.php
+++ b/samples/33_Chart_create_line.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,9 +31,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -35,7 +43,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -45,15 +53,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_LINECHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STACKED, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_LINECHART, // plotType
+    DataSeries::GROUPING_STACKED, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -61,15 +69,15 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_TOPRIGHT, null, false);
+$legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Stacked Line Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Stacked Line Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -89,7 +97,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_multiple_charts.php b/samples/33_Chart_create_multiple_charts.php
index d8ce1a20..fe20b76d 100644
--- a/samples/33_Chart_create_multiple_charts.php
+++ b/samples/33_Chart_create_multiple_charts.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,9 +31,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -35,7 +43,7 @@ $dataSeriesLabels1 = [
 //		Data values
 //		Data Marker
 $xAxisTickValues1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -45,15 +53,15 @@ $xAxisTickValues1 = [
 //		Data values
 //		Data Marker
 $dataSeriesValues1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_AREACHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
+$series1 = new DataSeries(
+    DataSeries::TYPE_AREACHART, // plotType
+    DataSeries::GROUPING_PERCENT_STACKED, // plotGrouping
     range(0, count($dataSeriesValues1) - 1), // plotOrder
     $dataSeriesLabels1, // plotLabel
     $xAxisTickValues1, // plotCategory
@@ -61,15 +69,15 @@ $series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set the series in the plot area
-$plotArea1 = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series1]);
+$plotArea1 = new PlotArea(null, [$series1]);
 //	Set the chart legend
-$legend1 = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_TOPRIGHT, null, false);
+$legend1 = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
-$title1 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test %age-Stacked Area Chart');
-$yAxisLabel1 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title1 = new Title('Test %age-Stacked Area Chart');
+$yAxisLabel1 = new Title('Value ($k)');
 
 //	Create the chart
-$chart1 = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart1 = new Chart(
     'chart1', // name
     $title1, // title
     $legend1, // legend
@@ -95,9 +103,9 @@ $worksheet->addChart($chart1);
 //		Data values
 //		Data Marker
 $dataSeriesLabels2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -107,7 +115,7 @@ $dataSeriesLabels2 = [
 //		Data values
 //		Data Marker
 $xAxisTickValues2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -117,15 +125,15 @@ $xAxisTickValues2 = [
 //		Data values
 //		Data Marker
 $dataSeriesValues2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_STANDARD, // plotGrouping
+$series2 = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_STANDARD, // plotGrouping
     range(0, count($dataSeriesValues2) - 1), // plotOrder
     $dataSeriesLabels2, // plotLabel
     $xAxisTickValues2, // plotCategory
@@ -133,18 +141,18 @@ $series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a vertical column rather than a horizontal bar graph
-$series2->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_COL);
+$series2->setPlotDirection(DataSeries::DIRECTION_COL);
 
 //	Set the series in the plot area
-$plotArea2 = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series2]);
+$plotArea2 = new PlotArea(null, [$series2]);
 //	Set the chart legend
-$legend2 = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend2 = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title2 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Column Chart');
-$yAxisLabel2 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title2 = new Title('Test Column Chart');
+$yAxisLabel2 = new Title('Value ($k)');
 
 //	Create the chart
-$chart2 = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart2 = new Chart(
     'chart2', // name
     $title2, // title
     $legend2, // legend
@@ -164,7 +172,7 @@ $worksheet->addChart($chart2);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_pie.php b/samples/33_Chart_create_pie.php
index c8a23909..895e0429 100644
--- a/samples/33_Chart_create_pie.php
+++ b/samples/33_Chart_create_pie.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,7 +31,7 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -33,7 +41,7 @@ $dataSeriesLabels1 = [
 //		Data values
 //		Data Marker
 $xAxisTickValues1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -43,12 +51,12 @@ $xAxisTickValues1 = [
 //		Data values
 //		Data Marker
 $dataSeriesValues1 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
 ];
 
 //	Build the dataseries
-$series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_PIECHART, // plotType
+$series1 = new DataSeries(
+    DataSeries::TYPE_PIECHART, // plotType
     null, // plotGrouping (Pie charts don't have any grouping)
     range(0, count($dataSeriesValues1) - 1), // plotOrder
     $dataSeriesLabels1, // plotLabel
@@ -57,19 +65,19 @@ $series1 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set up a layout object for the Pie chart
-$layout1 = new \PhpOffice\PhpSpreadsheet\Chart\Layout();
+$layout1 = new Chart\Layout();
 $layout1->setShowVal(true);
 $layout1->setShowPercent(true);
 
 //	Set the series in the plot area
-$plotArea1 = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea($layout1, [$series1]);
+$plotArea1 = new PlotArea($layout1, [$series1]);
 //	Set the chart legend
-$legend1 = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend1 = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title1 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Pie Chart');
+$title1 = new Title('Test Pie Chart');
 
 //	Create the chart
-$chart1 = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart1 = new Chart(
     'chart1', // name
     $title1, // title
     $legend1, // legend
@@ -95,7 +103,7 @@ $worksheet->addChart($chart1);
 //		Data values
 //		Data Marker
 $dataSeriesLabels2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -105,7 +113,7 @@ $dataSeriesLabels2 = [
 //		Data values
 //		Data Marker
 $xAxisTickValues2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -115,12 +123,12 @@ $xAxisTickValues2 = [
 //		Data values
 //		Data Marker
 $dataSeriesValues2 = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
 ];
 
 //	Build the dataseries
-$series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_DONUTCHART, // plotType
+$series2 = new DataSeries(
+    DataSeries::TYPE_DONUTCHART, // plotType
     null, // plotGrouping (Donut charts don't have any grouping)
     range(0, count($dataSeriesValues2) - 1), // plotOrder
     $dataSeriesLabels2, // plotLabel
@@ -129,17 +137,17 @@ $series2 = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set up a layout object for the Pie chart
-$layout2 = new \PhpOffice\PhpSpreadsheet\Chart\Layout();
+$layout2 = new Chart\Layout();
 $layout2->setShowVal(true);
 $layout2->setShowCatName(true);
 
 //	Set the series in the plot area
-$plotArea2 = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea($layout2, [$series2]);
+$plotArea2 = new PlotArea($layout2, [$series2]);
 
-$title2 = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Donut Chart');
+$title2 = new Title('Test Donut Chart');
 
 //	Create the chart
-$chart2 = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart2 = new Chart(
     'chart2', // name
     $title2, // title
     null, // legend
@@ -159,7 +167,7 @@ $worksheet->addChart($chart2);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_radar.php b/samples/33_Chart_create_radar.php
index 2a978792..df81f38c 100644
--- a/samples/33_Chart_create_radar.php
+++ b/samples/33_Chart_create_radar.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -31,8 +39,8 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -42,8 +50,8 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$13', null, 12), //	Jan to Dec
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -53,13 +61,13 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$13', null, 12),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$13', null, 12),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_RADARCHART, // plotType
+$series = new DataSeries(
+    DataSeries::TYPE_RADARCHART, // plotType
     null, // plotGrouping (Radar charts don't have any grouping)
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
@@ -67,21 +75,21 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
     $dataSeriesValues, // plotValues
     null, // plotDirection
     null, // smooth line
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::STYLE_MARKER  // plotStyle
+    DataSeries::STYLE_MARKER  // plotStyle
 );
 
 //	Set up a layout object for the Pie chart
-$layout = new \PhpOffice\PhpSpreadsheet\Chart\Layout();
+$layout = new Chart\Layout();
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea($layout, [$series]);
+$plotArea = new PlotArea($layout, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Radar Chart');
+$title = new Title('Test Radar Chart');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -101,7 +109,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_scatter.php b/samples/33_Chart_create_scatter.php
index 205113ab..df5564d7 100644
--- a/samples/33_Chart_create_scatter.php
+++ b/samples/33_Chart_create_scatter.php
@@ -1,9 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -23,13 +31,13 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -39,14 +47,14 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_SCATTERCHART, // plotType
+$series = new DataSeries(
+    DataSeries::TYPE_SCATTERCHART, // plotType
     null, // plotGrouping (Scatter charts don't have any grouping)
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
@@ -54,19 +62,19 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
     $dataSeriesValues, // plotValues
     null, // plotDirection
     null, // smooth line
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::STYLE_LINEMARKER  // plotStyle
+    DataSeries::STYLE_LINEMARKER  // plotStyle
 );
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_TOPRIGHT, null, false);
+$legend = new Legend(Legend::POSITION_TOPRIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Scatter Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Scatter Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
@@ -86,7 +94,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/33_Chart_create_stock.php b/samples/33_Chart_create_stock.php
index eea2a430..78d16e3f 100644
--- a/samples/33_Chart_create_stock.php
+++ b/samples/33_Chart_create_stock.php
@@ -1,9 +1,18 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 
 require __DIR__ . '/Header.php';
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -18,7 +27,7 @@ $worksheet->fromArray(
     'A1',
     true
 );
-$worksheet->getStyle('B2:E6')->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_NUMBER_00);
+$worksheet->getStyle('B2:E6')->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_NUMBER_00);
 
 //	Set the Labels for each data series we want to plot
 //		Datatype
@@ -28,10 +37,10 @@ $worksheet->getStyle('B2:E6')->getNumberFormat()->setFormatCode(\PhpOffice\PhpSp
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //Max / Open
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //Min / Close
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //Min Threshold / Min
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$E$1', null, 1), //Max Threshold / Max
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //Max / Open
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //Min / Close
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //Min Threshold / Min
+    new DataSeriesValues('String', 'Worksheet!$E$1', null, 1), //Max Threshold / Max
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -41,7 +50,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$6', null, 5), //	Counts
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$6', null, 5), //	Counts
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -51,15 +60,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$6', null, 5),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$6', null, 5),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$6', null, 5),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$E$2:$E$6', null, 5),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$6', null, 5),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$6', null, 5),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$6', null, 5),
+    new DataSeriesValues('Number', 'Worksheet!$E$2:$E$6', null, 5),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_STOCKCHART, // plotType
+$series = new DataSeries(
+    DataSeries::TYPE_STOCKCHART, // plotType
     null, // plotGrouping - if we set this to not null, then xlsx throws error
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
@@ -68,16 +77,16 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Stock Chart');
-$xAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Counts');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Values');
+$title = new Title('Test Stock Chart');
+$xAxisLabel = new Title('Counts');
+$yAxisLabel = new Title('Values');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'stock-chart', // name
     $title, // title
     $legend, // legend
@@ -97,7 +106,7 @@ $worksheet->addChart($chart);
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/34_Chart_update.php b/samples/34_Chart_update.php
index 0a3c6e5a..bed5241d 100644
--- a/samples/34_Chart_update.php
+++ b/samples/34_Chart_update.php
@@ -1,16 +1,18 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
 require __DIR__ . '/Header.php';
 
 // Create temporary file that will be read
 $sampleSpreadsheet = require __DIR__ . '/templates/chartSpreadsheet.php';
 $filename = $helper->getTemporaryFilename();
-$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($sampleSpreadsheet);
+$writer = new Xlsx($sampleSpreadsheet);
 $writer->save($filename);
 
 $helper->log('Load from Xlsx file');
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader('Xlsx');
+$reader = IOFactory::createReader('Xlsx');
 $reader->setIncludeCharts(true);
 $spreadsheet = $reader->load($filename);
 
@@ -29,7 +31,7 @@ $worksheet->fromArray(
 
 // Save Excel 2007 file
 $filename = $helper->getFilename(__FILE__);
-$writer = \PhpOffice\PhpSpreadsheet\IOFactory::createWriter($spreadsheet, 'Xlsx');
+$writer = IOFactory::createWriter($spreadsheet, 'Xlsx');
 $writer->setIncludeCharts(true);
 $callStartTime = microtime(true);
 $writer->save($filename);
diff --git a/samples/35_Chart_render.php b/samples/35_Chart_render.php
index b472f206..a63b28ef 100644
--- a/samples/35_Chart_render.php
+++ b/samples/35_Chart_render.php
@@ -1,14 +1,17 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Settings;
+
 require __DIR__ . '/Header.php';
 
 // Change these values to select the Rendering library that you wish to use
 // and its directory location on your server
-$rendererName = \PhpOffice\PhpSpreadsheet\Settings::CHART_RENDERER_JPGRAPH;
+$rendererName = Settings::CHART_RENDERER_JPGRAPH;
 $rendererLibrary = 'jpgraph3.5.0b1/src/';
 $rendererLibraryPath = '/php/libraries/Charts/' . $rendererLibrary;
 
-if (!\PhpOffice\PhpSpreadsheet\Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
+if (!Settings::setChartRenderer($rendererName, $rendererLibraryPath)) {
     $helper->log('NOTICE: Please set the $rendererName and $rendererLibraryPath values at the top of this script as appropriate for your directory structure');
 
     return;
@@ -35,7 +38,7 @@ foreach ($inputFileNames as $inputFileName) {
 
     $helper->log("Load Test from $inputFileType file ", $inputFileNameShort);
 
-    $reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+    $reader = IOFactory::createReader($inputFileType);
     $reader->setIncludeCharts(true);
     $spreadsheet = $reader->load($inputFileName);
 
diff --git a/samples/37_Page_layout_view.php b/samples/37_Page_layout_view.php
index 42cc1beb..2cdb3e12 100644
--- a/samples/37_Page_layout_view.php
+++ b/samples/37_Page_layout_view.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\SheetView;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -23,7 +26,7 @@ $spreadsheet->setActiveSheetIndex(0)
         ->setCellValue('B2', 'world!');
 
 // Set the page layout view as page layout
-$spreadsheet->getActiveSheet()->getSheetView()->setView(\PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_LAYOUT);
+$spreadsheet->getActiveSheet()->getSheetView()->setView(SheetView::SHEETVIEW_PAGE_LAYOUT);
 
 // Save
 $helper->write($spreadsheet, __FILE__);
diff --git a/samples/38_Clone_worksheet.php b/samples/38_Clone_worksheet.php
index aa555c39..b55b9025 100644
--- a/samples/38_Clone_worksheet.php
+++ b/samples/38_Clone_worksheet.php
@@ -1,10 +1,12 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
diff --git a/samples/39_Dropdown.php b/samples/39_Dropdown.php
index d4c0306e..bb68c3e9 100644
--- a/samples/39_Dropdown.php
+++ b/samples/39_Dropdown.php
@@ -1,10 +1,14 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\NamedRange;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -39,7 +43,7 @@ foreach ($continents as $key => $filename) {
     $spreadsheet->getActiveSheet()
             ->fromArray($countries, null, $column . '1');
     $spreadsheet->addNamedRange(
-        new \PhpOffice\PhpSpreadsheet\NamedRange(
+        new NamedRange(
             $continent,
             $spreadsheet->getActiveSheet(),
             $column . '1:' . $column . $countryCount
@@ -61,7 +65,7 @@ $spreadsheet->getActiveSheet()
         ->setVisible(false);
 
 $spreadsheet->addNamedRange(
-    new \PhpOffice\PhpSpreadsheet\NamedRange(
+    new NamedRange(
         'Continents',
         $spreadsheet->getActiveSheet(),
         $continentColumn . '1:' . $continentColumn . count($continents)
@@ -85,8 +89,8 @@ $spreadsheet->getActiveSheet()
 $validation = $spreadsheet->getActiveSheet()
         ->getCell('B1')
         ->getDataValidation();
-$validation->setType(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST)
-        ->setErrorStyle(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION)
+$validation->setType(DataValidation::TYPE_LIST)
+        ->setErrorStyle(DataValidation::STYLE_INFORMATION)
         ->setAllowBlank(false)
         ->setShowInputMessage(true)
         ->setShowErrorMessage(true)
@@ -106,8 +110,8 @@ $spreadsheet->getActiveSheet()
 $validation = $spreadsheet->getActiveSheet()
         ->getCell('B3')
         ->getDataValidation();
-$validation->setType(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST)
-        ->setErrorStyle(\PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION)
+$validation->setType(DataValidation::TYPE_LIST)
+        ->setErrorStyle(DataValidation::STYLE_INFORMATION)
         ->setAllowBlank(false)
         ->setShowInputMessage(true)
         ->setShowErrorMessage(true)
diff --git a/samples/40_Duplicate_style.php b/samples/40_Duplicate_style.php
index dca84817..4a006f90 100644
--- a/samples/40_Duplicate_style.php
+++ b/samples/40_Duplicate_style.php
@@ -1,15 +1,19 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style;
+
 require __DIR__ . '/Header.php';
 
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 
 $helper->log('Create styles array');
 $styles = [];
 for ($i = 0; $i < 10; ++$i) {
-    $style = new \PhpOffice\PhpSpreadsheet\Style();
+    $style = new Style();
     $style->getFont()->setSize($i + 4);
     $styles[] = $style;
 }
@@ -20,7 +24,7 @@ for ($col = 0; $col < 50; ++$col) {
     for ($row = 0; $row < 100; ++$row) {
         $str = ($row + $col);
         $style = $styles[$row % 10];
-        $coord = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col) . ($row + 1);
+        $coord = Cell::stringFromColumnIndex($col) . ($row + 1);
         $worksheet->setCellValue($coord, $str);
         $worksheet->duplicateStyle($style, $coord);
     }
diff --git a/samples/42_RichText.php b/samples/42_RichText.php
index 53b1c573..88db805c 100644
--- a/samples/42_RichText.php
+++ b/samples/42_RichText.php
@@ -1,10 +1,13 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Helper\Html as HtmlHelper;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 require __DIR__ . '/Header.php';
 
 // Create new Spreadsheet object
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -48,7 +51,7 @@ $html4 = 'H<sub>2</sub>SO<sub>4</sub> is the chemical formula for Sulphuric acid
 
 $html5 = '<strong>bold</strong>, <em>italic</em>, <strong><em>bold+italic</em></strong>';
 
-$wizard = new \PhpOffice\PhpSpreadsheet\Helper\Html();
+$wizard = new HtmlHelper();
 $richText = $wizard->toRichTextObject($html1);
 
 $spreadsheet->getActiveSheet()
diff --git a/samples/43_Merge_workbooks.php b/samples/43_Merge_workbooks.php
index 6173a2d5..57721a4a 100644
--- a/samples/43_Merge_workbooks.php
+++ b/samples/43_Merge_workbooks.php
@@ -1,17 +1,19 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+
 require __DIR__ . '/Header.php';
 
 $helper->log('Load MergeBook1 from Xlsx file');
 $filename1 = __DIR__ . '/templates/43mergeBook1.xlsx';
 $callStartTime = microtime(true);
-$spreadsheet1 = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename1);
+$spreadsheet1 = IOFactory::load($filename1);
 $helper->logRead('Xlsx', $filename1, $callStartTime);
 
 $helper->log('Load MergeBook2 from Xlsx file');
 $filename2 = __DIR__ . '/templates/43mergeBook2.xlsx';
 $callStartTime = microtime(true);
-$spreadsheet2 = \PhpOffice\PhpSpreadsheet\IOFactory::load($filename2);
+$spreadsheet2 = IOFactory::load($filename2);
 $helper->logRead('Xlsx', $filename2, $callStartTime);
 
 foreach ($spreadsheet2->getSheetNames() as $sheetName) {
diff --git a/samples/44_Worksheet_info.php b/samples/44_Worksheet_info.php
index 71849ca4..cacb9ae6 100644
--- a/samples/44_Worksheet_info.php
+++ b/samples/44_Worksheet_info.php
@@ -1,15 +1,18 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
+
 require __DIR__ . '/Header.php';
 
 // Create temporary file that will be read
 $sampleSpreadsheet = require __DIR__ . '/templates/sampleSpreadsheet.php';
 $filename = $helper->getTemporaryFilename();
-$writer = new \PhpOffice\PhpSpreadsheet\Writer\Xlsx($sampleSpreadsheet);
+$writer = new Xlsx($sampleSpreadsheet);
 $writer->save($filename);
 
-$inputFileType = \PhpOffice\PhpSpreadsheet\IOFactory::identify($filename);
-$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
+$inputFileType = IOFactory::identify($filename);
+$reader = IOFactory::createReader($inputFileType);
 $sheetList = $reader->listWorksheetNames($filename);
 $sheetInfo = $reader->listWorksheetInfo($filename);
 
diff --git a/samples/45_Quadratic_equation_solver.php b/samples/45_Quadratic_equation_solver.php
index f5e11e47..39f6685d 100644
--- a/samples/45_Quadratic_equation_solver.php
+++ b/samples/45_Quadratic_equation_solver.php
@@ -1,4 +1,6 @@
 <?php
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 require __DIR__ . '/Header.php';
 ?>
 <form action="45_Quadratic_equation_solver.php" method="POST">
@@ -28,13 +30,13 @@ if (isset($_POST['submit'])) {
         echo '<hr /><b>Roots:</b><br />';
 
         $discriminantFormula = '=POWER(' . $_POST['B'] . ',2) - (4 * ' . $_POST['A'] . ' * ' . $_POST['C'] . ')';
-        $discriminant = \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->calculateFormula($discriminantFormula);
+        $discriminant = Calculation::getInstance()->calculateFormula($discriminantFormula);
 
         $r1Formula = '=IMDIV(IMSUM(-' . $_POST['B'] . ',IMSQRT(' . $discriminant . ')),2 * ' . $_POST['A'] . ')';
         $r2Formula = '=IF(' . $discriminant . '=0,"Only one root",IMDIV(IMSUB(-' . $_POST['B'] . ',IMSQRT(' . $discriminant . ')),2 * ' . $_POST['A'] . '))';
 
-        echo \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->calculateFormula($r1Formula) . '<br />';
-        echo \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->calculateFormula($r2Formula) . '<br />';
+        echo Calculation::getInstance()->calculateFormula($r1Formula) . '<br />';
+        echo Calculation::getInstance()->calculateFormula($r2Formula) . '<br />';
         $callEndTime = microtime(true);
         $helper->logEndingNotes();
     }
diff --git a/samples/Header.php b/samples/Header.php
index b406ba1b..e9ada9f7 100644
--- a/samples/Header.php
+++ b/samples/Header.php
@@ -2,11 +2,13 @@
 /**
  * Header file.
  */
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+
 error_reporting(E_ALL);
 
 require_once __DIR__ . '/../src/Bootstrap.php';
 
-$helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+$helper = new Sample();
 if (!defined('EOL')) {
     define('EOL', $helper->isCli() ? PHP_EOL : '<br />');
 }
diff --git a/samples/templates/chartSpreadsheet.php b/samples/templates/chartSpreadsheet.php
index f6fb8b00..c462f533 100644
--- a/samples/templates/chartSpreadsheet.php
+++ b/samples/templates/chartSpreadsheet.php
@@ -1,6 +1,14 @@
 <?php
 
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
+$spreadsheet = new Spreadsheet();
 $worksheet = $spreadsheet->getActiveSheet();
 $worksheet->fromArray(
     [
@@ -20,9 +28,9 @@ $worksheet->fromArray(
 //		Data values
 //		Data Marker
 $dataSeriesLabels = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
+    new DataSeriesValues('String', 'Worksheet!$B$1', null, 1), //	2010
+    new DataSeriesValues('String', 'Worksheet!$C$1', null, 1), //	2011
+    new DataSeriesValues('String', 'Worksheet!$D$1', null, 1), //	2012
 ];
 //	Set the X-Axis Labels
 //		Datatype
@@ -32,7 +40,7 @@ $dataSeriesLabels = [
 //		Data values
 //		Data Marker
 $xAxisTickValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
+    new DataSeriesValues('String', 'Worksheet!$A$2:$A$5', null, 4), //	Q1 to Q4
 ];
 //	Set the Data values for each data series we want to plot
 //		Datatype
@@ -42,15 +50,15 @@ $xAxisTickValues = [
 //		Data values
 //		Data Marker
 $dataSeriesValues = [
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
-    new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$B$2:$B$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$C$2:$C$5', null, 4),
+    new DataSeriesValues('Number', 'Worksheet!$D$2:$D$5', null, 4),
 ];
 
 //	Build the dataseries
-$series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::TYPE_BARCHART, // plotType
-    \PhpOffice\PhpSpreadsheet\Chart\DataSeries::GROUPING_CLUSTERED, // plotGrouping
+$series = new DataSeries(
+    DataSeries::TYPE_BARCHART, // plotType
+    DataSeries::GROUPING_CLUSTERED, // plotGrouping
     range(0, count($dataSeriesValues) - 1), // plotOrder
     $dataSeriesLabels, // plotLabel
     $xAxisTickValues, // plotCategory
@@ -58,18 +66,18 @@ $series = new \PhpOffice\PhpSpreadsheet\Chart\DataSeries(
 );
 //	Set additional dataseries parameters
 //		Make it a horizontal bar rather than a vertical column graph
-$series->setPlotDirection(\PhpOffice\PhpSpreadsheet\Chart\DataSeries::DIRECTION_BAR);
+$series->setPlotDirection(DataSeries::DIRECTION_BAR);
 
 //	Set the series in the plot area
-$plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea(null, [$series]);
+$plotArea = new PlotArea(null, [$series]);
 //	Set the chart legend
-$legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend(\PhpOffice\PhpSpreadsheet\Chart\Legend::POSITION_RIGHT, null, false);
+$legend = new Legend(Legend::POSITION_RIGHT, null, false);
 
-$title = new \PhpOffice\PhpSpreadsheet\Chart\Title('Test Bar Chart');
-$yAxisLabel = new \PhpOffice\PhpSpreadsheet\Chart\Title('Value ($k)');
+$title = new Title('Test Bar Chart');
+$yAxisLabel = new Title('Value ($k)');
 
 //	Create the chart
-$chart = new \PhpOffice\PhpSpreadsheet\Chart(
+$chart = new Chart(
     'chart1', // name
     $title, // title
     $legend, // legend
diff --git a/samples/templates/largeSpreadsheet.php b/samples/templates/largeSpreadsheet.php
index 76ecb5d0..2205bf6f 100644
--- a/samples/templates/largeSpreadsheet.php
+++ b/samples/templates/largeSpreadsheet.php
@@ -1,8 +1,10 @@
 <?php
 
 // Create new Spreadsheet object
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set properties');
diff --git a/samples/templates/sampleSpreadsheet.php b/samples/templates/sampleSpreadsheet.php
index 67bd9fd9..0ab6ebc1 100644
--- a/samples/templates/sampleSpreadsheet.php
+++ b/samples/templates/sampleSpreadsheet.php
@@ -1,8 +1,21 @@
 <?php
 
 // Create new Spreadsheet object
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+
 $helper->log('Create new Spreadsheet object');
-$spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+$spreadsheet = new Spreadsheet();
 
 // Set document properties
 $helper->log('Set document properties');
@@ -18,8 +31,8 @@ $spreadsheet->getProperties()->setCreator('Maarten Balliauw')
 $helper->log('Add some data');
 $spreadsheet->setActiveSheetIndex(0);
 $spreadsheet->getActiveSheet()->setCellValue('B1', 'Invoice');
-$spreadsheet->getActiveSheet()->setCellValue('D1', \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, date('m'), date('d'), date('Y'))));
-$spreadsheet->getActiveSheet()->getStyle('D1')->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX15);
+$spreadsheet->getActiveSheet()->setCellValue('D1', Date::PHPToExcel(gmmktime(0, 0, 0, date('m'), date('d'), date('Y'))));
+$spreadsheet->getActiveSheet()->getStyle('D1')->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_XLSX15);
 $spreadsheet->getActiveSheet()->setCellValue('E1', '#12566');
 
 $spreadsheet->getActiveSheet()->setCellValue('A3', 'Product Id');
@@ -81,13 +94,13 @@ $spreadsheet->getActiveSheet()->getComment('E13')->getFillColor()->setRGB('EEEEE
 
 // Add rich-text string
 $helper->log('Add rich-text string');
-$richText = new \PhpOffice\PhpSpreadsheet\RichText();
+$richText = new RichText();
 $richText->createText('This invoice is ');
 
 $payable = $richText->createTextRun('payable within thirty days after the end of the month');
 $payable->getFont()->setBold(true);
 $payable->getFont()->setItalic(true);
-$payable->getFont()->setColor(new \PhpOffice\PhpSpreadsheet\Style\Color(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_DARKGREEN));
+$payable->getFont()->setColor(new Color(Color::COLOR_DARKGREEN));
 
 $richText->createText(', unless specified otherwise on the invoice.');
 
@@ -105,7 +118,7 @@ $spreadsheet->getActiveSheet()->protectCells('A3:E13', 'PhpSpreadsheet');
 
 // Set cell number formats
 $helper->log('Set cell number formats');
-$spreadsheet->getActiveSheet()->getStyle('E4:E13')->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
+$spreadsheet->getActiveSheet()->getStyle('E4:E13')->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE);
 
 // Set column widths
 $helper->log('Set column widths');
@@ -118,23 +131,23 @@ $helper->log('Set fonts');
 $spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->setName('Candara');
 $spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->setSize(20);
 $spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->setBold(true);
-$spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE);
-$spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_WHITE);
+$spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->setUnderline(Font::UNDERLINE_SINGLE);
+$spreadsheet->getActiveSheet()->getStyle('B1')->getFont()->getColor()->setARGB(Color::COLOR_WHITE);
 
-$spreadsheet->getActiveSheet()->getStyle('D1')->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_WHITE);
-$spreadsheet->getActiveSheet()->getStyle('E1')->getFont()->getColor()->setARGB(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_WHITE);
+$spreadsheet->getActiveSheet()->getStyle('D1')->getFont()->getColor()->setARGB(Color::COLOR_WHITE);
+$spreadsheet->getActiveSheet()->getStyle('E1')->getFont()->getColor()->setARGB(Color::COLOR_WHITE);
 
 $spreadsheet->getActiveSheet()->getStyle('D13')->getFont()->setBold(true);
 $spreadsheet->getActiveSheet()->getStyle('E13')->getFont()->setBold(true);
 
 // Set alignments
 $helper->log('Set alignments');
-$spreadsheet->getActiveSheet()->getStyle('D11')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
-$spreadsheet->getActiveSheet()->getStyle('D12')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
-$spreadsheet->getActiveSheet()->getStyle('D13')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
+$spreadsheet->getActiveSheet()->getStyle('D11')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
+$spreadsheet->getActiveSheet()->getStyle('D12')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
+$spreadsheet->getActiveSheet()->getStyle('D13')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
 
-$spreadsheet->getActiveSheet()->getStyle('A18')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY);
-$spreadsheet->getActiveSheet()->getStyle('A18')->getAlignment()->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER);
+$spreadsheet->getActiveSheet()->getStyle('A18')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_JUSTIFY);
+$spreadsheet->getActiveSheet()->getStyle('A18')->getAlignment()->setVertical(Alignment::VERTICAL_CENTER);
 
 $spreadsheet->getActiveSheet()->getStyle('B5')->getAlignment()->setShrinkToFit(true);
 
@@ -143,7 +156,7 @@ $helper->log('Set thin black border outline around column');
 $styleThinBlackBorderOutline = [
     'borders' => [
         'outline' => [
-            'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN,
+            'style' => Border::BORDER_THIN,
             'color' => ['argb' => 'FF000000'],
         ],
     ],
@@ -155,7 +168,7 @@ $helper->log('Set thick brown border outline around Total');
 $styleThickBrownBorderOutline = [
     'borders' => [
         'outline' => [
-            'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK,
+            'style' => Border::BORDER_THICK,
             'color' => ['argb' => 'FF993300'],
         ],
     ],
@@ -164,7 +177,7 @@ $spreadsheet->getActiveSheet()->getStyle('D13:E13')->applyFromArray($styleThickB
 
 // Set fills
 $helper->log('Set fills');
-$spreadsheet->getActiveSheet()->getStyle('A1:E1')->getFill()->setFillType(\PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID);
+$spreadsheet->getActiveSheet()->getStyle('A1:E1')->getFill()->setFillType(Fill::FILL_SOLID);
 $spreadsheet->getActiveSheet()->getStyle('A1:E1')->getFill()->getStartColor()->setARGB('FF808080');
 
 // Set style for header row using alternative method
@@ -175,15 +188,15 @@ $spreadsheet->getActiveSheet()->getStyle('A3:E3')->applyFromArray(
                 'bold' => true,
             ],
             'alignment' => [
-                'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT,
+                'horizontal' => Alignment::HORIZONTAL_RIGHT,
             ],
             'borders' => [
                 'top' => [
-                    'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN,
+                    'style' => Border::BORDER_THIN,
                 ],
             ],
             'fill' => [
-                'type' => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR,
+                'type' => Fill::FILL_GRADIENT_LINEAR,
                 'rotation' => 90,
                 'startcolor' => [
                     'argb' => 'FFA0A0A0',
@@ -198,11 +211,11 @@ $spreadsheet->getActiveSheet()->getStyle('A3:E3')->applyFromArray(
 $spreadsheet->getActiveSheet()->getStyle('A3')->applyFromArray(
     [
             'alignment' => [
-                'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT,
+                'horizontal' => Alignment::HORIZONTAL_LEFT,
             ],
             'borders' => [
                 'left' => [
-                    'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN,
+                    'style' => Border::BORDER_THIN,
                 ],
             ],
         ]
@@ -211,7 +224,7 @@ $spreadsheet->getActiveSheet()->getStyle('A3')->applyFromArray(
 $spreadsheet->getActiveSheet()->getStyle('B3')->applyFromArray(
     [
             'alignment' => [
-                'horizontal' => \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT,
+                'horizontal' => Alignment::HORIZONTAL_LEFT,
             ],
         ]
 );
@@ -220,7 +233,7 @@ $spreadsheet->getActiveSheet()->getStyle('E3')->applyFromArray(
     [
             'borders' => [
                 'right' => [
-                    'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN,
+                    'style' => Border::BORDER_THIN,
                 ],
             ],
         ]
@@ -228,24 +241,24 @@ $spreadsheet->getActiveSheet()->getStyle('E3')->applyFromArray(
 
 // Unprotect a cell
 $helper->log('Unprotect a cell');
-$spreadsheet->getActiveSheet()->getStyle('B1')->getProtection()->setLocked(\PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED);
+$spreadsheet->getActiveSheet()->getStyle('B1')->getProtection()->setLocked(Protection::PROTECTION_UNPROTECTED);
 
 // Add a hyperlink to the sheet
 $helper->log('Add a hyperlink to an external website');
 $spreadsheet->getActiveSheet()->setCellValue('E26', 'www.phpexcel.net');
 $spreadsheet->getActiveSheet()->getCell('E26')->getHyperlink()->setUrl('http://www.phpexcel.net');
 $spreadsheet->getActiveSheet()->getCell('E26')->getHyperlink()->setTooltip('Navigate to website');
-$spreadsheet->getActiveSheet()->getStyle('E26')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
+$spreadsheet->getActiveSheet()->getStyle('E26')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
 
 $helper->log('Add a hyperlink to another cell on a different worksheet within the workbook');
 $spreadsheet->getActiveSheet()->setCellValue('E27', 'Terms and conditions');
 $spreadsheet->getActiveSheet()->getCell('E27')->getHyperlink()->setUrl("sheet://'Terms and conditions'!A1");
 $spreadsheet->getActiveSheet()->getCell('E27')->getHyperlink()->setTooltip('Review terms and conditions');
-$spreadsheet->getActiveSheet()->getStyle('E27')->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
+$spreadsheet->getActiveSheet()->getStyle('E27')->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
 
 // Add a drawing to the worksheet
 $helper->log('Add a drawing to the worksheet');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\Drawing();
+$drawing = new Drawing();
 $drawing->setName('Logo');
 $drawing->setDescription('Logo');
 $drawing->setPath(__DIR__ . '/../images/officelogo.jpg');
@@ -254,7 +267,7 @@ $drawing->setWorksheet($spreadsheet->getActiveSheet());
 
 // Add a drawing to the worksheet
 $helper->log('Add a drawing to the worksheet');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\Drawing();
+$drawing = new Drawing();
 $drawing->setName('Paid');
 $drawing->setDescription('Paid');
 $drawing->setPath(__DIR__ . '/../images/paid.png');
@@ -267,7 +280,7 @@ $drawing->setWorksheet($spreadsheet->getActiveSheet());
 
 // Add a drawing to the worksheet
 $helper->log('Add a drawing to the worksheet');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\Drawing();
+$drawing = new Drawing();
 $drawing->setName('PhpSpreadsheet logo');
 $drawing->setDescription('PhpSpreadsheet logo');
 $drawing->setPath(__DIR__ . '/../images/PhpSpreadsheet_logo.png');
@@ -290,8 +303,8 @@ $spreadsheet->getActiveSheet()->getHeaderFooter()->setOddFooter('&L&B' . $spread
 
 // Set page orientation and size
 $helper->log('Set page orientation and size');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_PORTRAIT);
-$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_PORTRAIT);
+$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(PageSetup::PAPERSIZE_A4);
 
 // Rename first worksheet
 $helper->log('Rename first worksheet');
@@ -330,13 +343,13 @@ $helper->log('Set fonts');
 $spreadsheet->getActiveSheet()->getStyle('A1')->getFont()->setName('Candara');
 $spreadsheet->getActiveSheet()->getStyle('A1')->getFont()->setSize(20);
 $spreadsheet->getActiveSheet()->getStyle('A1')->getFont()->setBold(true);
-$spreadsheet->getActiveSheet()->getStyle('A1')->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE);
+$spreadsheet->getActiveSheet()->getStyle('A1')->getFont()->setUnderline(Font::UNDERLINE_SINGLE);
 
 $spreadsheet->getActiveSheet()->getStyle('A3:A6')->getFont()->setSize(8);
 
 // Add a drawing to the worksheet
 $helper->log('Add a drawing to the worksheet');
-$drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\Drawing();
+$drawing = new Drawing();
 $drawing->setName('Terms and conditions');
 $drawing->setDescription('Terms and conditions');
 $drawing->setPath(__DIR__ . '/../images/termsconditions.jpg');
@@ -345,8 +358,8 @@ $drawing->setWorksheet($spreadsheet->getActiveSheet());
 
 // Set page orientation and size
 $helper->log('Set page orientation and size');
-$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
-$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4);
+$spreadsheet->getActiveSheet()->getPageSetup()->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
+$spreadsheet->getActiveSheet()->getPageSetup()->setPaperSize(PageSetup::PAPERSIZE_A4);
 
 // Rename second worksheet
 $helper->log('Rename second worksheet');
diff --git a/src/Bootstrap.php b/src/Bootstrap.php
index b7062b5a..455999fc 100644
--- a/src/Bootstrap.php
+++ b/src/Bootstrap.php
@@ -26,6 +26,7 @@
  */
 
 // This sucks, but we have to try to find the composer autoloader
+
 $paths = [
     __DIR__ . '/../vendor/autoload.php', // In case PhpSpreadsheet is cloned directly
     __DIR__ . '/../../../autoload.php', // In case PhpSpreadsheet is a composer dependency.
diff --git a/src/PhpSpreadsheet/Calculation.php b/src/PhpSpreadsheet/Calculation.php
index 46414a4a..684070ab 100644
--- a/src/PhpSpreadsheet/Calculation.php
+++ b/src/PhpSpreadsheet/Calculation.php
@@ -2066,7 +2066,7 @@ class Calculation
         }
 
         if (!isset(self::$instance) || (self::$instance === null)) {
-            self::$instance = new \PhpOffice\PhpSpreadsheet\Calculation();
+            self::$instance = new self();
         }
 
         return self::$instance;
@@ -2084,7 +2084,7 @@ class Calculation
 
     /**
      * Flush the calculation cache for any existing instance of this class
-     *        but only if a \PhpOffice\PhpSpreadsheet\Calculation instance exists.
+     *        but only if a Calculation instance exists.
      */
     public function flushInstance()
     {
diff --git a/src/PhpSpreadsheet/Calculation/Database.php b/src/PhpSpreadsheet/Calculation/Database.php
index 72e2a88e..b490dc00 100644
--- a/src/PhpSpreadsheet/Calculation/Database.php
+++ b/src/PhpSpreadsheet/Calculation/Database.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -116,12 +118,12 @@ class Database
                 $k = array_search($criteriaName, $fieldNames);
                 if (isset($dataValues[$k])) {
                     $dataValue = $dataValues[$k];
-                    $dataValue = (is_string($dataValue)) ? \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($dataValue)) : $dataValue;
+                    $dataValue = (is_string($dataValue)) ? Calculation::wrapResult(strtoupper($dataValue)) : $dataValue;
                     $testConditionList = str_replace('[:' . $criteriaName . ']', $dataValue, $testConditionList);
                 }
             }
             //    evaluate the criteria against the row data
-            $result = \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue('=' . $testConditionList);
+            $result = Calculation::getInstance()->_calculateFormulaValue('=' . $testConditionList);
             //    If the row failed to meet the criteria, remove it from the database
             if (!$result) {
                 unset($database[$dataRow]);
diff --git a/src/PhpSpreadsheet/Calculation/DateTime.php b/src/PhpSpreadsheet/Calculation/DateTime.php
index 782b0828..d8a1d000 100644
--- a/src/PhpSpreadsheet/Calculation/DateTime.php
+++ b/src/PhpSpreadsheet/Calculation/DateTime.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -90,7 +93,7 @@ class DateTime
                 return Functions::VALUE();
             }
             if ((is_object($dateValue)) && ($dateValue instanceof \DateTime)) {
-                $dateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($dateValue);
+                $dateValue = Date::PHPToExcel($dateValue);
             } else {
                 $saveReturnDateType = Functions::getReturnDateType();
                 Functions::setReturnDateType(Functions::RETURNDATE_EXCEL);
@@ -122,7 +125,7 @@ class DateTime
     private static function adjustDateByMonths($dateValue = 0, $adjustmentMonths = 0)
     {
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
         $oMonth = (int) $PHPDateObject->format('m');
         $oYear = (int) $PHPDateObject->format('Y');
 
@@ -172,7 +175,7 @@ class DateTime
         $retValue = false;
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
-                $retValue = (float) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(time());
+                $retValue = (float) Date::PHPToExcel(time());
                 break;
             case Functions::RETURNDATE_PHP_NUMERIC:
                 $retValue = (int) time();
@@ -210,16 +213,16 @@ class DateTime
         $saveTimeZone = date_default_timezone_get();
         date_default_timezone_set('UTC');
         $retValue = false;
-        $excelDateTime = floor(\PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(time()));
+        $excelDateTime = floor(Date::PHPToExcel(time()));
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
                 $retValue = (float) $excelDateTime;
                 break;
             case Functions::RETURNDATE_PHP_NUMERIC:
-                $retValue = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateTime);
+                $retValue = (int) Date::excelToTimestamp($excelDateTime);
                 break;
             case Functions::RETURNDATE_PHP_OBJECT:
-                $retValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($excelDateTime);
+                $retValue = Date::excelToDateTimeObject($excelDateTime);
                 break;
         }
         date_default_timezone_set($saveTimeZone);
@@ -285,16 +288,16 @@ class DateTime
         $day = Functions::flattenSingleValue($day);
 
         if (($month !== null) && (!is_numeric($month))) {
-            $month = \PhpOffice\PhpSpreadsheet\Shared\Date::monthStringToNumber($month);
+            $month = Date::monthStringToNumber($month);
         }
 
         if (($day !== null) && (!is_numeric($day))) {
-            $day = \PhpOffice\PhpSpreadsheet\Shared\Date::dayStringToNumber($day);
+            $day = Date::dayStringToNumber($day);
         }
 
-        $year = ($year !== null) ? \PhpOffice\PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($year) : 0;
-        $month = ($month !== null) ? \PhpOffice\PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($month) : 0;
-        $day = ($day !== null) ? \PhpOffice\PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($day) : 0;
+        $year = ($year !== null) ? StringHelper::testStringAsNumeric($year) : 0;
+        $month = ($month !== null) ? StringHelper::testStringAsNumeric($month) : 0;
+        $day = ($day !== null) ? StringHelper::testStringAsNumeric($day) : 0;
         if ((!is_numeric($year)) ||
             (!is_numeric($month)) ||
             (!is_numeric($day))) {
@@ -304,7 +307,7 @@ class DateTime
         $month = (int) $month;
         $day = (int) $day;
 
-        $baseYear = \PhpOffice\PhpSpreadsheet\Shared\Date::getExcelCalendar();
+        $baseYear = Date::getExcelCalendar();
         // Validate parameters
         if ($year < ($baseYear - 1900)) {
             return Functions::NAN();
@@ -334,14 +337,14 @@ class DateTime
         }
 
         // Execute function
-        $excelDateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel($year, $month, $day);
+        $excelDateValue = Date::formattedPHPToExcel($year, $month, $day);
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
                 return (float) $excelDateValue;
             case Functions::RETURNDATE_PHP_NUMERIC:
-                return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue);
+                return (int) Date::excelToTimestamp($excelDateValue);
             case Functions::RETURNDATE_PHP_OBJECT:
-                return \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($excelDateValue);
+                return Date::excelToDateTimeObject($excelDateValue);
         }
     }
 
@@ -427,14 +430,14 @@ class DateTime
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
                 $date = 0;
-                $calendar = \PhpOffice\PhpSpreadsheet\Shared\Date::getExcelCalendar();
-                if ($calendar != \PhpOffice\PhpSpreadsheet\Shared\Date::CALENDAR_WINDOWS_1900) {
+                $calendar = Date::getExcelCalendar();
+                if ($calendar != Date::CALENDAR_WINDOWS_1900) {
                     $date = 1;
                 }
 
-                return (float) \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel($calendar, 1, $date, $hour, $minute, $second);
+                return (float) Date::formattedPHPToExcel($calendar, 1, $date, $hour, $minute, $second);
             case Functions::RETURNDATE_PHP_NUMERIC:
-                return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(1970, 1, 1, $hour, $minute, $second)); // -2147468400; //    -2147472000 + 3600
+                return (int) Date::excelToTimestamp(Date::formattedPHPToExcel(1970, 1, 1, $hour, $minute, $second)); // -2147468400; //    -2147472000 + 3600
             case Functions::RETURNDATE_PHP_OBJECT:
                 $dayAdjust = 0;
                 if ($hour < 0) {
@@ -570,7 +573,7 @@ class DateTime
                 return Functions::VALUE();
             }
             $excelDateValue = floor(
-                \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                Date::formattedPHPToExcel(
                     $PHPDateArray['year'],
                     $PHPDateArray['month'],
                     $PHPDateArray['day'],
@@ -583,7 +586,7 @@ class DateTime
                 case Functions::RETURNDATE_EXCEL:
                     return (float) $excelDateValue;
                 case Functions::RETURNDATE_PHP_NUMERIC:
-                    return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue);
+                    return (int) Date::excelToTimestamp($excelDateValue);
                 case Functions::RETURNDATE_PHP_OBJECT:
                     return new \DateTime($PHPDateArray['year'] . '-' . $PHPDateArray['month'] . '-' . $PHPDateArray['day'] . ' 00:00:00');
             }
@@ -629,7 +632,7 @@ class DateTime
         $PHPDateArray = date_parse($timeValue);
         if (($PHPDateArray !== false) && ($PHPDateArray['error_count'] == 0)) {
             if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE) {
-                $excelDateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                $excelDateValue = Date::formattedPHPToExcel(
                     $PHPDateArray['year'],
                     $PHPDateArray['month'],
                     $PHPDateArray['day'],
@@ -638,14 +641,14 @@ class DateTime
                     $PHPDateArray['second']
                 );
             } else {
-                $excelDateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(1900, 1, 1, $PHPDateArray['hour'], $PHPDateArray['minute'], $PHPDateArray['second']) - 1;
+                $excelDateValue = Date::formattedPHPToExcel(1900, 1, 1, $PHPDateArray['hour'], $PHPDateArray['minute'], $PHPDateArray['second']) - 1;
             }
 
             switch (Functions::getReturnDateType()) {
                 case Functions::RETURNDATE_EXCEL:
                     return (float) $excelDateValue;
                 case Functions::RETURNDATE_PHP_NUMERIC:
-                    return (int) $phpDateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue + 25569) - 3600;
+                    return (int) $phpDateValue = Date::excelToTimestamp($excelDateValue + 25569) - 3600;
                 case Functions::RETURNDATE_PHP_OBJECT:
                     return new \DateTime('1900-01-01 ' . $PHPDateArray['hour'] . ':' . $PHPDateArray['minute'] . ':' . $PHPDateArray['second']);
             }
@@ -686,12 +689,12 @@ class DateTime
         // Execute function
         $difference = $endDate - $startDate;
 
-        $PHPStartDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($startDate);
+        $PHPStartDateObject = Date::excelToDateTimeObject($startDate);
         $startDays = $PHPStartDateObject->format('j');
         $startMonths = $PHPStartDateObject->format('n');
         $startYears = $PHPStartDateObject->format('Y');
 
-        $PHPEndDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
+        $PHPEndDateObject = Date::excelToDateTimeObject($endDate);
         $endDays = $PHPEndDateObject->format('j');
         $endMonths = $PHPEndDateObject->format('n');
         $endYears = $PHPEndDateObject->format('Y');
@@ -818,12 +821,12 @@ class DateTime
         }
 
         // Execute function
-        $PHPStartDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($startDate);
+        $PHPStartDateObject = Date::excelToDateTimeObject($startDate);
         $startDay = $PHPStartDateObject->format('j');
         $startMonth = $PHPStartDateObject->format('n');
         $startYear = $PHPStartDateObject->format('Y');
 
-        $PHPEndDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
+        $PHPEndDateObject = Date::excelToDateTimeObject($endDate);
         $endDay = $PHPEndDateObject->format('j');
         $endMonth = $PHPEndDateObject->format('n');
         $endYear = $PHPEndDateObject->format('Y');
@@ -1116,9 +1119,9 @@ class DateTime
             case Functions::RETURNDATE_EXCEL:
                 return (float) $endDate;
             case Functions::RETURNDATE_PHP_NUMERIC:
-                return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($endDate);
+                return (int) Date::excelToTimestamp($endDate);
             case Functions::RETURNDATE_PHP_OBJECT:
-                return \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
+                return Date::excelToDateTimeObject($endDate);
         }
     }
 
@@ -1151,7 +1154,7 @@ class DateTime
         }
 
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
 
         return (int) $PHPDateObject->format('j');
     }
@@ -1195,7 +1198,7 @@ class DateTime
         }
 
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
         $DoW = $PHPDateObject->format('w');
 
         $firstDay = 1;
@@ -1271,7 +1274,7 @@ class DateTime
         }
 
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
         $dayOfYear = $PHPDateObject->format('z');
         $PHPDateObject->modify('-' . $dayOfYear . ' days');
         $firstDayOfFirstWeek = $PHPDateObject->format('w');
@@ -1314,7 +1317,7 @@ class DateTime
         }
 
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
 
         return (int) $PHPDateObject->format('n');
     }
@@ -1346,7 +1349,7 @@ class DateTime
         }
 
         // Execute function
-        $PHPDateObject = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
+        $PHPDateObject = Date::excelToDateTimeObject($dateValue);
 
         return (int) $PHPDateObject->format('Y');
     }
@@ -1387,7 +1390,7 @@ class DateTime
         } elseif ($timeValue < 0.0) {
             return Functions::NAN();
         }
-        $timeValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);
+        $timeValue = Date::excelToTimestamp($timeValue);
 
         return (int) gmdate('G', $timeValue);
     }
@@ -1428,7 +1431,7 @@ class DateTime
         } elseif ($timeValue < 0.0) {
             return Functions::NAN();
         }
-        $timeValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);
+        $timeValue = Date::excelToTimestamp($timeValue);
 
         return (int) gmdate('i', $timeValue);
     }
@@ -1469,7 +1472,7 @@ class DateTime
         } elseif ($timeValue < 0.0) {
             return Functions::NAN();
         }
-        $timeValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);
+        $timeValue = Date::excelToTimestamp($timeValue);
 
         return (int) gmdate('s', $timeValue);
     }
@@ -1513,9 +1516,9 @@ class DateTime
 
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
-                return (float) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject);
+                return (float) Date::PHPToExcel($PHPDateObject);
             case Functions::RETURNDATE_PHP_NUMERIC:
-                return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject));
+                return (int) Date::excelToTimestamp(Date::PHPToExcel($PHPDateObject));
             case Functions::RETURNDATE_PHP_OBJECT:
                 return $PHPDateObject;
         }
@@ -1562,9 +1565,9 @@ class DateTime
 
         switch (Functions::getReturnDateType()) {
             case Functions::RETURNDATE_EXCEL:
-                return (float) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject);
+                return (float) Date::PHPToExcel($PHPDateObject);
             case Functions::RETURNDATE_PHP_NUMERIC:
-                return (int) \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject));
+                return (int) Date::excelToTimestamp(Date::PHPToExcel($PHPDateObject));
             case Functions::RETURNDATE_PHP_OBJECT:
                 return $PHPDateObject;
         }
diff --git a/src/PhpSpreadsheet/Calculation/Exception.php b/src/PhpSpreadsheet/Calculation/Exception.php
index 6a9711fc..fa1b91c6 100644
--- a/src/PhpSpreadsheet/Calculation/Exception.php
+++ b/src/PhpSpreadsheet/Calculation/Exception.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +26,7 @@ namespace PhpOffice\PhpSpreadsheet\Calculation;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Exception extends \PhpOffice\PhpSpreadsheet\Exception
+class Exception extends PhpSpreadsheetException
 {
     /**
      * Error handler callback.
diff --git a/src/PhpSpreadsheet/Calculation/ExceptionHandler.php b/src/PhpSpreadsheet/Calculation/ExceptionHandler.php
index a8b82405..fd2233c9 100644
--- a/src/PhpSpreadsheet/Calculation/ExceptionHandler.php
+++ b/src/PhpSpreadsheet/Calculation/ExceptionHandler.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation\Exception as CalculationException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -31,7 +33,7 @@ class ExceptionHandler
      */
     public function __construct()
     {
-        set_error_handler([\PhpOffice\PhpSpreadsheet\Calculation\Exception::class, 'errorHandlerCallback'], E_ALL);
+        set_error_handler([CalculationException::class, 'errorHandlerCallback'], E_ALL);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Calculation/Financial.php b/src/PhpSpreadsheet/Calculation/Financial.php
index 4c80a684..305494be 100644
--- a/src/PhpSpreadsheet/Calculation/Financial.php
+++ b/src/PhpSpreadsheet/Calculation/Financial.php
@@ -3,6 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
 /* FINANCIAL_MAX_ITERATIONS */
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+
 define('FINANCIAL_MAX_ITERATIONS', 128);
 
 /* FINANCIAL_PRECISION */
@@ -64,10 +66,10 @@ class Financial
     {
         $months = 12 / $frequency;
 
-        $result = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($maturity);
+        $result = Date::excelToDateTimeObject($maturity);
         $eom = self::isLastDayOfMonth($result);
 
-        while ($settlement < \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($result)) {
+        while ($settlement < Date::PHPToExcel($result)) {
             $result->modify('-' . $months . ' months');
         }
         if ($next) {
@@ -78,7 +80,7 @@ class Financial
             $result->modify('-1 day');
         }
 
-        return \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($result);
+        return Date::PHPToExcel($result);
     }
 
     private static function isValidFrequency($frequency)
diff --git a/src/PhpSpreadsheet/Calculation/Functions.php b/src/PhpSpreadsheet/Calculation/Functions.php
index 88346ed0..b13e987d 100644
--- a/src/PhpSpreadsheet/Calculation/Functions.php
+++ b/src/PhpSpreadsheet/Calculation/Functions.php
@@ -3,6 +3,8 @@
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
 /* MAX_VALUE */
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 define('MAX_VALUE', 1.2e308);
 
 /* 2 / PI */
@@ -298,7 +300,7 @@ class Functions
         }
         if (!in_array($condition[0], ['>', '<', '='])) {
             if (!is_numeric($condition)) {
-                $condition = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($condition));
+                $condition = Calculation::wrapResult(strtoupper($condition));
             }
 
             return '=' . $condition;
@@ -308,7 +310,7 @@ class Functions
 
         if (!is_numeric($operand)) {
             $operand = str_replace('"', '""', $operand);
-            $operand = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($operand));
+            $operand = Calculation::wrapResult(strtoupper($operand));
         }
 
         return $operator . $operand;
diff --git a/src/PhpSpreadsheet/Calculation/Logical.php b/src/PhpSpreadsheet/Calculation/Logical.php
index 25bacafc..5492cc6e 100644
--- a/src/PhpSpreadsheet/Calculation/Logical.php
+++ b/src/PhpSpreadsheet/Calculation/Logical.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -98,9 +100,9 @@ class Logical
                 $returnValue = $returnValue && ($arg != 0);
             } elseif (is_string($arg)) {
                 $arg = strtoupper($arg);
-                if (($arg == 'TRUE') || ($arg == \PhpOffice\PhpSpreadsheet\Calculation::getTRUE())) {
+                if (($arg == 'TRUE') || ($arg == Calculation::getTRUE())) {
                     $arg = true;
-                } elseif (($arg == 'FALSE') || ($arg == \PhpOffice\PhpSpreadsheet\Calculation::getFALSE())) {
+                } elseif (($arg == 'FALSE') || ($arg == Calculation::getFALSE())) {
                     $arg = false;
                 } else {
                     return Functions::VALUE();
@@ -155,9 +157,9 @@ class Logical
                 $returnValue = $returnValue || ($arg != 0);
             } elseif (is_string($arg)) {
                 $arg = strtoupper($arg);
-                if (($arg == 'TRUE') || ($arg == \PhpOffice\PhpSpreadsheet\Calculation::getTRUE())) {
+                if (($arg == 'TRUE') || ($arg == Calculation::getTRUE())) {
                     $arg = true;
-                } elseif (($arg == 'FALSE') || ($arg == \PhpOffice\PhpSpreadsheet\Calculation::getFALSE())) {
+                } elseif (($arg == 'FALSE') || ($arg == Calculation::getFALSE())) {
                     $arg = false;
                 } else {
                     return Functions::VALUE();
@@ -200,9 +202,9 @@ class Logical
         $logical = Functions::flattenSingleValue($logical);
         if (is_string($logical)) {
             $logical = strtoupper($logical);
-            if (($logical == 'TRUE') || ($logical == \PhpOffice\PhpSpreadsheet\Calculation::getTRUE())) {
+            if (($logical == 'TRUE') || ($logical == Calculation::getTRUE())) {
                 return false;
-            } elseif (($logical == 'FALSE') || ($logical == \PhpOffice\PhpSpreadsheet\Calculation::getFALSE())) {
+            } elseif (($logical == 'FALSE') || ($logical == Calculation::getFALSE())) {
                 return true;
             }
 
diff --git a/src/PhpSpreadsheet/Calculation/LookupRef.php b/src/PhpSpreadsheet/Calculation/LookupRef.php
index 8359b0ba..010aea93 100644
--- a/src/PhpSpreadsheet/Calculation/LookupRef.php
+++ b/src/PhpSpreadsheet/Calculation/LookupRef.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Cell;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -72,7 +75,7 @@ class LookupRef
         }
         if ((!is_bool($referenceStyle)) || $referenceStyle) {
             $rowRelative = $columnRelative = '$';
-            $column = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column - 1);
+            $column = Cell::stringFromColumnIndex($column - 1);
             if (($relativity == 2) || ($relativity == 4)) {
                 $columnRelative = '';
             }
@@ -118,7 +121,7 @@ class LookupRef
             foreach ($cellAddress as $columnKey => $value) {
                 $columnKey = preg_replace('/[^a-z]/i', '', $columnKey);
 
-                return (int) \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnKey);
+                return (int) Cell::columnIndexFromString($columnKey);
             }
         } else {
             if (strpos($cellAddress, '!') !== false) {
@@ -130,14 +133,14 @@ class LookupRef
                 $endAddress = preg_replace('/[^a-z]/i', '', $endAddress);
                 $returnValue = [];
                 do {
-                    $returnValue[] = (int) \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($startAddress);
+                    $returnValue[] = (int) Cell::columnIndexFromString($startAddress);
                 } while ($startAddress++ != $endAddress);
 
                 return $returnValue;
             }
             $cellAddress = preg_replace('/[^a-z]/i', '', $cellAddress);
 
-            return (int) \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($cellAddress);
+            return (int) Cell::columnIndexFromString($cellAddress);
         }
     }
 
@@ -164,7 +167,7 @@ class LookupRef
 
         reset($cellAddress);
         $isMatrix = (is_numeric(key($cellAddress)));
-        list($columns, $rows) = \PhpOffice\PhpSpreadsheet\Calculation::_getMatrixDimensions($cellAddress);
+        list($columns, $rows) = Calculation::_getMatrixDimensions($cellAddress);
 
         if ($isMatrix) {
             return $rows;
@@ -245,7 +248,7 @@ class LookupRef
 
         reset($cellAddress);
         $isMatrix = (is_numeric(key($cellAddress)));
-        list($columns, $rows) = \PhpOffice\PhpSpreadsheet\Calculation::_getMatrixDimensions($cellAddress);
+        list($columns, $rows) = Calculation::_getMatrixDimensions($cellAddress);
 
         if ($isMatrix) {
             return $columns;
@@ -264,11 +267,11 @@ class LookupRef
      *
      * @param string $linkURL Value to check, is also the value returned when no error
      * @param string $displayName Value to return when testValue is an error condition
-     * @param \PhpOffice\PhpSpreadsheet\Cell $pCell The cell to set the hyperlink in
+     * @param Cell $pCell The cell to set the hyperlink in
      *
      * @return mixed The value of $displayName (or $linkURL if $displayName was blank)
      */
-    public static function HYPERLINK($linkURL = '', $displayName = null, \PhpOffice\PhpSpreadsheet\Cell $pCell = null)
+    public static function HYPERLINK($linkURL = '', $displayName = null, Cell $pCell = null)
     {
         $linkURL = (is_null($linkURL)) ? '' : Functions::flattenSingleValue($linkURL);
         $displayName = (is_null($displayName)) ? '' : Functions::flattenSingleValue($displayName);
@@ -299,13 +302,13 @@ class LookupRef
      * NOTE - INDIRECT() does not yet support the optional a1 parameter introduced in Excel 2010
      *
      * @param cellAddress $cellAddress The cell address of the current cell (containing this formula)
-     * @param \PhpOffice\PhpSpreadsheet\Cell $pCell The current cell (containing this formula)
+     * @param Cell $pCell The current cell (containing this formula)
      *
      * @return mixed The cells referenced by cellAddress
      *
      * @todo    Support for the optional a1 parameter introduced in Excel 2010
      */
-    public static function INDIRECT($cellAddress = null, \PhpOffice\PhpSpreadsheet\Cell $pCell = null)
+    public static function INDIRECT($cellAddress = null, Cell $pCell = null)
     {
         $cellAddress = Functions::flattenSingleValue($cellAddress);
         if (is_null($cellAddress) || $cellAddress === '') {
@@ -318,9 +321,9 @@ class LookupRef
             list($cellAddress1, $cellAddress2) = explode(':', $cellAddress);
         }
 
-        if ((!preg_match('/^' . \PhpOffice\PhpSpreadsheet\Calculation::CALCULATION_REGEXP_CELLREF . '$/i', $cellAddress1, $matches)) ||
-            ((!is_null($cellAddress2)) && (!preg_match('/^' . \PhpOffice\PhpSpreadsheet\Calculation::CALCULATION_REGEXP_CELLREF . '$/i', $cellAddress2, $matches)))) {
-            if (!preg_match('/^' . \PhpOffice\PhpSpreadsheet\Calculation::CALCULATION_REGEXP_NAMEDRANGE . '$/i', $cellAddress1, $matches)) {
+        if ((!preg_match('/^' . Calculation::CALCULATION_REGEXP_CELLREF . '$/i', $cellAddress1, $matches)) ||
+            ((!is_null($cellAddress2)) && (!preg_match('/^' . Calculation::CALCULATION_REGEXP_CELLREF . '$/i', $cellAddress2, $matches)))) {
+            if (!preg_match('/^' . Calculation::CALCULATION_REGEXP_NAMEDRANGE . '$/i', $cellAddress1, $matches)) {
                 return Functions::REF();
             }
 
@@ -332,7 +335,7 @@ class LookupRef
                 $pSheet = $pCell->getWorksheet();
             }
 
-            return \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->extractNamedRange($cellAddress, $pSheet, false);
+            return Calculation::getInstance()->extractNamedRange($cellAddress, $pSheet, false);
         }
 
         if (strpos($cellAddress, '!') !== false) {
@@ -343,7 +346,7 @@ class LookupRef
             $pSheet = $pCell->getWorksheet();
         }
 
-        return \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->extractCellRange($cellAddress, $pSheet, false);
+        return Calculation::getInstance()->extractCellRange($cellAddress, $pSheet, false);
     }
 
     /**
@@ -374,11 +377,11 @@ class LookupRef
      * @param mixed $columns
      * @param null|mixed $height
      * @param null|mixed $width
-     * @param \PhpOffice\PhpSpreadsheet\Cell $pCell
+     * @param Cell $pCell
      *
      * @return string A reference to a cell or range of cells
      */
-    public static function OFFSET($cellAddress = null, $rows = 0, $columns = 0, $height = null, $width = null, \PhpOffice\PhpSpreadsheet\Cell $pCell = null)
+    public static function OFFSET($cellAddress = null, $rows = 0, $columns = 0, $height = null, $width = null, Cell $pCell = null)
     {
         $rows = Functions::flattenSingleValue($rows);
         $columns = Functions::flattenSingleValue($columns);
@@ -402,23 +405,23 @@ class LookupRef
         } else {
             $startCell = $endCell = $cellAddress;
         }
-        list($startCellColumn, $startCellRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($startCell);
-        list($endCellColumn, $endCellRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($endCell);
+        list($startCellColumn, $startCellRow) = Cell::coordinateFromString($startCell);
+        list($endCellColumn, $endCellRow) = Cell::coordinateFromString($endCell);
 
         $startCellRow += $rows;
-        $startCellColumn = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($startCellColumn) - 1;
+        $startCellColumn = Cell::columnIndexFromString($startCellColumn) - 1;
         $startCellColumn += $columns;
 
         if (($startCellRow <= 0) || ($startCellColumn < 0)) {
             return Functions::REF();
         }
-        $endCellColumn = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($endCellColumn) - 1;
+        $endCellColumn = Cell::columnIndexFromString($endCellColumn) - 1;
         if (($width != null) && (!is_object($width))) {
             $endCellColumn = $startCellColumn + $width - 1;
         } else {
             $endCellColumn += $columns;
         }
-        $startCellColumn = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($startCellColumn);
+        $startCellColumn = Cell::stringFromColumnIndex($startCellColumn);
 
         if (($height != null) && (!is_object($height))) {
             $endCellRow = $startCellRow + $height - 1;
@@ -429,7 +432,7 @@ class LookupRef
         if (($endCellRow <= 0) || ($endCellColumn < 0)) {
             return Functions::REF();
         }
-        $endCellColumn = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($endCellColumn);
+        $endCellColumn = Cell::stringFromColumnIndex($endCellColumn);
 
         $cellAddress = $startCellColumn . $startCellRow;
         if (($startCellColumn != $endCellColumn) || ($startCellRow != $endCellRow)) {
@@ -442,7 +445,7 @@ class LookupRef
             $pSheet = $pCell->getWorksheet();
         }
 
-        return \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->extractCellRange($cellAddress, $pSheet, false);
+        return Calculation::getInstance()->extractCellRange($cellAddress, $pSheet, false);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Calculation/MathTrig.php b/src/PhpSpreadsheet/Calculation/MathTrig.php
index 6ea7ba66..25200205 100644
--- a/src/PhpSpreadsheet/Calculation/MathTrig.php
+++ b/src/PhpSpreadsheet/Calculation/MathTrig.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -567,10 +571,10 @@ class MathTrig
         }
 
         try {
-            $matrix = new \PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix($matrixData);
+            $matrix = new Matrix($matrixData);
 
             return $matrix->det();
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $ex) {
+        } catch (PhpSpreadsheetException $ex) {
             return Functions::VALUE();
         }
     }
@@ -621,10 +625,10 @@ class MathTrig
         }
 
         try {
-            $matrix = new \PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix($matrixData);
+            $matrix = new Matrix($matrixData);
 
             return $matrix->inverse()->getArray();
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $ex) {
+        } catch (PhpSpreadsheetException $ex) {
             return Functions::VALUE();
         }
     }
@@ -663,7 +667,7 @@ class MathTrig
                 }
                 ++$rowA;
             }
-            $matrixA = new \PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix($matrixAData);
+            $matrixA = new Matrix($matrixAData);
             $rowB = 0;
             foreach ($matrixData2 as $matrixRow) {
                 if (!is_array($matrixRow)) {
@@ -679,14 +683,14 @@ class MathTrig
                 }
                 ++$rowB;
             }
-            $matrixB = new \PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix($matrixBData);
+            $matrixB = new Matrix($matrixBData);
 
             if ($columnA != $rowB) {
                 return Functions::VALUE();
             }
 
             return $matrixA->times($matrixB)->getArray();
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $ex) {
+        } catch (PhpSpreadsheetException $ex) {
             return Functions::VALUE();
         }
     }
@@ -1231,11 +1235,11 @@ class MathTrig
         foreach ($aArgs as $key => $arg) {
             if (!is_numeric($arg)) {
                 $arg = str_replace('"', '""', $arg);
-                $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                $arg = Calculation::wrapResult(strtoupper($arg));
             }
 
             $testCondition = '=' . $arg . $condition;
-            if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+            if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                 // Is it a value within our criteria
                 $returnValue += $sumArgs[$key];
             }
@@ -1280,10 +1284,10 @@ class MathTrig
             // Loop through arguments
             foreach ($aArgs as $key => $arg) {
                 if (!is_numeric($arg)) {
-                    $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                    $arg = Calculation::wrapResult(strtoupper($arg));
                 }
                 $testCondition = '=' . $arg . $condition;
-                if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+                if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                     // Is it a value within our criteria
                     $returnValue += $sumArgs[$key];
                 }
diff --git a/src/PhpSpreadsheet/Calculation/Statistical.php b/src/PhpSpreadsheet/Calculation/Statistical.php
index 2f743e70..b379b1ba 100644
--- a/src/PhpSpreadsheet/Calculation/Statistical.php
+++ b/src/PhpSpreadsheet/Calculation/Statistical.php
@@ -3,6 +3,9 @@
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
 /* LOG_GAMMA_X_MAX_VALUE */
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Shared\Trend\Trend;
+
 define('LOG_GAMMA_X_MAX_VALUE', 2.55e305);
 
 /* XMININ */
@@ -883,10 +886,10 @@ class Statistical
         $aCount = 0;
         foreach ($aArgs as $key => $arg) {
             if (!is_numeric($arg)) {
-                $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                $arg = Calculation::wrapResult(strtoupper($arg));
             }
             $testCondition = '=' . $arg . $condition;
-            if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+            if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                 if ((is_null($returnValue)) || ($arg > $returnValue)) {
                     $returnValue += $arg;
                     ++$aCount;
@@ -1194,7 +1197,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getCorrelation();
     }
@@ -1317,10 +1320,10 @@ class Statistical
         // Loop through arguments
         foreach ($aArgs as $arg) {
             if (!is_numeric($arg)) {
-                $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                $arg = Calculation::wrapResult(strtoupper($arg));
             }
             $testCondition = '=' . $arg . $condition;
-            if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+            if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                 // Is it a value within our criteria
                 ++$returnValue;
             }
@@ -1355,7 +1358,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getCovariance();
     }
@@ -1649,7 +1652,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getValueOfYForX($xValue);
     }
@@ -1829,7 +1832,7 @@ class Statistical
         $newValues = Functions::flattenArray($newValues);
         $const = (is_null($const)) ? true : (bool) Functions::flattenSingleValue($const);
 
-        $bestFitExponential = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
+        $bestFitExponential = Trend::calculate(Trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
         if (empty($newValues)) {
             $newValues = $bestFitExponential->getXValues();
         }
@@ -1956,7 +1959,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getIntersect();
     }
@@ -2084,7 +2087,7 @@ class Statistical
             return 0;
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues, $const);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues, $const);
         if ($stats) {
             return [
                 [
@@ -2153,7 +2156,7 @@ class Statistical
             return 1;
         }
 
-        $bestFitExponential = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
+        $bestFitExponential = Trend::calculate(Trend::TREND_EXPONENTIAL, $yValues, $xValues, $const);
         if ($stats) {
             return [
                 [
@@ -2347,10 +2350,10 @@ class Statistical
         // Loop through arguments
         foreach ($aArgs as $key => $arg) {
             if (!is_numeric($arg)) {
-                $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                $arg = Calculation::wrapResult(strtoupper($arg));
             }
             $testCondition = '=' . $arg . $condition;
-            if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+            if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                 if ((is_null($returnValue)) || ($arg > $returnValue)) {
                     $returnValue = $arg;
                 }
@@ -2510,10 +2513,10 @@ class Statistical
         // Loop through arguments
         foreach ($aArgs as $key => $arg) {
             if (!is_numeric($arg)) {
-                $arg = \PhpOffice\PhpSpreadsheet\Calculation::wrapResult(strtoupper($arg));
+                $arg = Calculation::wrapResult(strtoupper($arg));
             }
             $testCondition = '=' . $arg . $condition;
-            if (\PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
+            if (Calculation::getInstance()->_calculateFormulaValue($testCondition)) {
                 if ((is_null($returnValue)) || ($arg < $returnValue)) {
                     $returnValue = $arg;
                 }
@@ -3005,7 +3008,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getGoodnessOfFit();
     }
@@ -3075,7 +3078,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getSlope();
     }
@@ -3379,7 +3382,7 @@ class Statistical
             return Functions::DIV0();
         }
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues);
 
         return $bestFitLinear->getStdevOfResiduals();
     }
@@ -3530,7 +3533,7 @@ class Statistical
         $newValues = Functions::flattenArray($newValues);
         $const = (is_null($const)) ? true : (bool) Functions::flattenSingleValue($const);
 
-        $bestFitLinear = \PhpOffice\PhpSpreadsheet\Shared\trend\trend::calculate(\PhpOffice\PhpSpreadsheet\Shared\trend\trend::TREND_LINEAR, $yValues, $xValues, $const);
+        $bestFitLinear = Trend::calculate(Trend::TREND_LINEAR, $yValues, $xValues, $const);
         if (empty($newValues)) {
             $newValues = $bestFitLinear->getXValues();
         }
diff --git a/src/PhpSpreadsheet/Calculation/TextData.php b/src/PhpSpreadsheet/Calculation/TextData.php
index fd9cd7a9..ed4b8b9c 100644
--- a/src/PhpSpreadsheet/Calculation/TextData.php
+++ b/src/PhpSpreadsheet/Calculation/TextData.php
@@ -2,6 +2,11 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -67,7 +72,7 @@ class TextData
         $stringValue = Functions::flattenSingleValue($stringValue);
 
         if (is_bool($stringValue)) {
-            return ($stringValue) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            return ($stringValue) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         if (self::$invalidChars == null) {
@@ -92,7 +97,7 @@ class TextData
     {
         $stringValue = Functions::flattenSingleValue($stringValue);
         if (is_bool($stringValue)) {
-            return ($stringValue) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            return ($stringValue) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         if (is_string($stringValue) || is_numeric($stringValue)) {
@@ -119,7 +124,7 @@ class TextData
             if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE) {
                 $characters = (int) $characters;
             } else {
-                $characters = ($characters) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+                $characters = ($characters) ? Calculation::getTRUE() : Calculation::getFALSE();
             }
         }
 
@@ -147,7 +152,7 @@ class TextData
                 if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE) {
                     $arg = (int) $arg;
                 } else {
-                    $arg = ($arg) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+                    $arg = ($arg) ? Calculation::getTRUE() : Calculation::getFALSE();
                 }
             }
             $returnValue .= $arg;
@@ -191,7 +196,7 @@ class TextData
             $value = MathTrig::MROUND($value, $round);
         }
 
-        return \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString($value, $mask);
+        return NumberFormat::toFormattedString($value, $mask);
     }
 
     /**
@@ -211,11 +216,11 @@ class TextData
 
         if (!is_bool($needle)) {
             if (is_bool($haystack)) {
-                $haystack = ($haystack) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+                $haystack = ($haystack) ? Calculation::getTRUE() : Calculation::getFALSE();
             }
 
-            if (($offset > 0) && (\PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($haystack) > $offset)) {
-                if (\PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($needle) == 0) {
+            if (($offset > 0) && (StringHelper::countCharacters($haystack) > $offset)) {
+                if (StringHelper::countCharacters($needle) == 0) {
                     return $offset;
                 }
 
@@ -246,11 +251,11 @@ class TextData
 
         if (!is_bool($needle)) {
             if (is_bool($haystack)) {
-                $haystack = ($haystack) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+                $haystack = ($haystack) ? Calculation::getTRUE() : Calculation::getFALSE();
             }
 
-            if (($offset > 0) && (\PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($haystack) > $offset)) {
-                if (\PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($needle) == 0) {
+            if (($offset > 0) && (StringHelper::countCharacters($haystack) > $offset)) {
+                if (StringHelper::countCharacters($needle) == 0) {
                     return $offset;
                 }
 
@@ -314,7 +319,7 @@ class TextData
         }
 
         if (is_bool($value)) {
-            $value = ($value) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $value = ($value) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         return mb_substr($value, 0, $chars, 'UTF-8');
@@ -340,7 +345,7 @@ class TextData
         }
 
         if (is_bool($value)) {
-            $value = ($value) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $value = ($value) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         if (empty($chars)) {
@@ -368,7 +373,7 @@ class TextData
         }
 
         if (is_bool($value)) {
-            $value = ($value) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $value = ($value) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         return mb_substr($value, mb_strlen($value, 'UTF-8') - $chars, $chars, 'UTF-8');
@@ -386,7 +391,7 @@ class TextData
         $value = Functions::flattenSingleValue($value);
 
         if (is_bool($value)) {
-            $value = ($value) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $value = ($value) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
         return mb_strlen($value, 'UTF-8');
@@ -406,10 +411,10 @@ class TextData
         $mixedCaseString = Functions::flattenSingleValue($mixedCaseString);
 
         if (is_bool($mixedCaseString)) {
-            $mixedCaseString = ($mixedCaseString) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $mixedCaseString = ($mixedCaseString) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
-        return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::strToLower($mixedCaseString);
+        return StringHelper::strToLower($mixedCaseString);
     }
 
     /**
@@ -426,10 +431,10 @@ class TextData
         $mixedCaseString = Functions::flattenSingleValue($mixedCaseString);
 
         if (is_bool($mixedCaseString)) {
-            $mixedCaseString = ($mixedCaseString) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $mixedCaseString = ($mixedCaseString) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
-        return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::strToUpper($mixedCaseString);
+        return StringHelper::strToUpper($mixedCaseString);
     }
 
     /**
@@ -446,10 +451,10 @@ class TextData
         $mixedCaseString = Functions::flattenSingleValue($mixedCaseString);
 
         if (is_bool($mixedCaseString)) {
-            $mixedCaseString = ($mixedCaseString) ? \PhpOffice\PhpSpreadsheet\Calculation::getTRUE() : \PhpOffice\PhpSpreadsheet\Calculation::getFALSE();
+            $mixedCaseString = ($mixedCaseString) ? Calculation::getTRUE() : Calculation::getFALSE();
         }
 
-        return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::strToTitle($mixedCaseString);
+        return StringHelper::strToTitle($mixedCaseString);
     }
 
     /**
@@ -543,11 +548,11 @@ class TextData
         $value = Functions::flattenSingleValue($value);
         $format = Functions::flattenSingleValue($format);
 
-        if ((is_string($value)) && (!is_numeric($value)) && \PhpOffice\PhpSpreadsheet\Shared\Date::isDateTimeFormatCode($format)) {
+        if ((is_string($value)) && (!is_numeric($value)) && Date::isDateTimeFormatCode($format)) {
             $value = DateTime::DATEVALUE($value);
         }
 
-        return (string) \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString($value, $format);
+        return (string) NumberFormat::toFormattedString($value, $format);
     }
 
     /**
@@ -563,9 +568,9 @@ class TextData
 
         if (!is_numeric($value)) {
             $numberValue = str_replace(
-                \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getThousandsSeparator(),
+                StringHelper::getThousandsSeparator(),
                 '',
-                trim($value, " \t\n\r\0\x0B" . \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getCurrencyCode())
+                trim($value, " \t\n\r\0\x0B" . StringHelper::getCurrencyCode())
             );
             if (is_numeric($numberValue)) {
                 return (float) $numberValue;
diff --git a/src/PhpSpreadsheet/Calculation/Token/Stack.php b/src/PhpSpreadsheet/Calculation/Token/Stack.php
index efa63011..16b8635f 100644
--- a/src/PhpSpreadsheet/Calculation/Token/Stack.php
+++ b/src/PhpSpreadsheet/Calculation/Token/Stack.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Calculation\Token;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -65,7 +67,7 @@ class Stack
             'reference' => $reference,
         ];
         if ($type == 'Function') {
-            $localeFunction = \PhpOffice\PhpSpreadsheet\Calculation::localeFunc($value);
+            $localeFunction = Calculation::localeFunc($value);
             if ($localeFunction != $value) {
                 $this->stack[($this->count - 1)]['localeValue'] = $localeFunction;
             }
diff --git a/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php b/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
index ba960839..f7f161fd 100644
--- a/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
+++ b/src/PhpSpreadsheet/Cell/AdvancedValueBinder.php
@@ -2,6 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheet\Cell;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,36 +36,36 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
     /**
      * Bind value to a cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Cell $cell Cell to bind value to
+     * @param Cell $cell Cell to bind value to
      * @param mixed $value Value to bind in cell
      *
      * @return bool
      */
-    public function bindValue(\PhpOffice\PhpSpreadsheet\Cell $cell, $value = null)
+    public function bindValue(Cell $cell, $value = null)
     {
         // sanitize UTF-8 strings
         if (is_string($value)) {
-            $value = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::sanitizeUTF8($value);
+            $value = StringHelper::sanitizeUTF8($value);
         }
 
         // Find out data type
         $dataType = parent::dataTypeForValue($value);
 
         // Style logic - strings
-        if ($dataType === DataType::TYPE_STRING && !$value instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+        if ($dataType === DataType::TYPE_STRING && !$value instanceof RichText) {
             //    Test for booleans using locale-setting
-            if ($value == \PhpOffice\PhpSpreadsheet\Calculation::getTRUE()) {
+            if ($value == Calculation::getTRUE()) {
                 $cell->setValueExplicit(true, DataType::TYPE_BOOL);
 
                 return true;
-            } elseif ($value == \PhpOffice\PhpSpreadsheet\Calculation::getFALSE()) {
+            } elseif ($value == Calculation::getFALSE()) {
                 $cell->setValueExplicit(false, DataType::TYPE_BOOL);
 
                 return true;
             }
 
             // Check for number in scientific format
-            if (preg_match('/^' . \PhpOffice\PhpSpreadsheet\Calculation::CALCULATION_REGEXP_NUMBER . '$/', $value)) {
+            if (preg_match('/^' . Calculation::CALCULATION_REGEXP_NUMBER . '$/', $value)) {
                 $cell->setValueExplicit((float) $value, DataType::TYPE_NUMERIC);
 
                 return true;
@@ -98,15 +105,15 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
                 $cell->setValueExplicit($value, DataType::TYPE_NUMERIC);
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
-                    ->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_PERCENTAGE_00);
+                    ->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_PERCENTAGE_00);
 
                 return true;
             }
 
             // Check for currency
-            $currencyCode = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getCurrencyCode();
-            $decimalSeparator = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getDecimalSeparator();
-            $thousandsSeparator = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getThousandsSeparator();
+            $currencyCode = StringHelper::getCurrencyCode();
+            $decimalSeparator = StringHelper::getDecimalSeparator();
+            $thousandsSeparator = StringHelper::getThousandsSeparator();
             if (preg_match('/^' . preg_quote($currencyCode) . ' *(\d{1,3}(' . preg_quote($thousandsSeparator) . '\d{3})*|(\d+))(' . preg_quote($decimalSeparator) . '\d{2})?$/', $value)) {
                 // Convert value to number
                 $value = (float) trim(str_replace([$currencyCode, $thousandsSeparator, $decimalSeparator], ['', '', '.'], $value));
@@ -114,7 +121,7 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
                     ->getNumberFormat()->setFormatCode(
-                        str_replace('$', $currencyCode, \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE)
+                        str_replace('$', $currencyCode, NumberFormat::FORMAT_CURRENCY_USD_SIMPLE)
                     );
 
                 return true;
@@ -124,7 +131,7 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
                 $cell->setValueExplicit($value, DataType::TYPE_NUMERIC);
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
-                    ->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
+                    ->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
 
                 return true;
             }
@@ -137,7 +144,7 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
                 $cell->setValueExplicit($days, DataType::TYPE_NUMERIC);
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
-                    ->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME3);
+                    ->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_TIME3);
 
                 return true;
             }
@@ -151,13 +158,13 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
                 $cell->setValueExplicit($days, DataType::TYPE_NUMERIC);
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
-                    ->getNumberFormat()->setFormatCode(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME4);
+                    ->getNumberFormat()->setFormatCode(NumberFormat::FORMAT_DATE_TIME4);
 
                 return true;
             }
 
             // Check for datetime, e.g. '2008-12-31', '2008-12-31 15:59', '2008-12-31 15:59:10'
-            if (($d = \PhpOffice\PhpSpreadsheet\Shared\Date::stringToExcel($value)) !== false) {
+            if (($d = Date::stringToExcel($value)) !== false) {
                 // Convert value to number
                 $cell->setValueExplicit($d, DataType::TYPE_NUMERIC);
                 // Determine style. Either there is a time part or not. Look for ':'
@@ -174,7 +181,7 @@ class AdvancedValueBinder extends DefaultValueBinder implements IValueBinder
 
             // Check for newline character "\n"
             if (strpos($value, "\n") !== false) {
-                $value = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::sanitizeUTF8($value);
+                $value = StringHelper::sanitizeUTF8($value);
                 $cell->setValueExplicit($value, DataType::TYPE_STRING);
                 // Set style
                 $cell->getWorksheet()->getStyle($cell->getCoordinate())
diff --git a/src/PhpSpreadsheet/Cell/DataType.php b/src/PhpSpreadsheet/Cell/DataType.php
index 2f41b66c..b308fe74 100644
--- a/src/PhpSpreadsheet/Cell/DataType.php
+++ b/src/PhpSpreadsheet/Cell/DataType.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Cell;
 
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -71,13 +74,13 @@ class DataType
      */
     public static function checkString($pValue)
     {
-        if ($pValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+        if ($pValue instanceof RichText) {
             // TODO: Sanitize Rich-Text string (max. character count is 32,767)
             return $pValue;
         }
 
         // string must never be longer than 32,767 characters, truncate if necessary
-        $pValue = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::substring($pValue, 0, 32767);
+        $pValue = StringHelper::substring($pValue, 0, 32767);
 
         // we require that newline is represented as "\n" in core, not as "\r\n" or "\r"
         $pValue = str_replace(["\r\n", "\r"], "\n", $pValue);
diff --git a/src/PhpSpreadsheet/Cell/DefaultValueBinder.php b/src/PhpSpreadsheet/Cell/DefaultValueBinder.php
index f9e7729f..a0fc5209 100644
--- a/src/PhpSpreadsheet/Cell/DefaultValueBinder.php
+++ b/src/PhpSpreadsheet/Cell/DefaultValueBinder.php
@@ -2,6 +2,11 @@
 
 namespace PhpOffice\PhpSpreadsheet\Cell;
 
+use DateTime;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,21 +34,21 @@ class DefaultValueBinder implements IValueBinder
     /**
      * Bind value to a cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Cell $cell Cell to bind value to
+     * @param Cell $cell Cell to bind value to
      * @param mixed $value Value to bind in cell
      *
      * @return bool
      */
-    public function bindValue(\PhpOffice\PhpSpreadsheet\Cell $cell, $value = null)
+    public function bindValue(Cell $cell, $value = null)
     {
         // sanitize UTF-8 strings
         if (is_string($value)) {
-            $value = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::sanitizeUTF8($value);
+            $value = StringHelper::sanitizeUTF8($value);
         } elseif (is_object($value)) {
             // Handle any objects that might be injected
-            if ($value instanceof \DateTime) {
+            if ($value instanceof DateTime) {
                 $value = $value->format('Y-m-d H:i:s');
-            } elseif (!($value instanceof \PhpOffice\PhpSpreadsheet\RichText)) {
+            } elseif (!($value instanceof RichText)) {
                 $value = (string) $value;
             }
         }
@@ -69,7 +74,7 @@ class DefaultValueBinder implements IValueBinder
             return DataType::TYPE_NULL;
         } elseif ($pValue === '') {
             return DataType::TYPE_STRING;
-        } elseif ($pValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+        } elseif ($pValue instanceof RichText) {
             return DataType::TYPE_INLINE;
         } elseif ($pValue[0] === '=' && strlen($pValue) > 1) {
             return DataType::TYPE_FORMULA;
diff --git a/src/PhpSpreadsheet/Cell/IValueBinder.php b/src/PhpSpreadsheet/Cell/IValueBinder.php
index 191eb844..72813b2c 100644
--- a/src/PhpSpreadsheet/Cell/IValueBinder.php
+++ b/src/PhpSpreadsheet/Cell/IValueBinder.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Cell;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,10 +31,10 @@ interface IValueBinder
     /**
      * Bind value to a cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Cell $cell Cell to bind value to
+     * @param Cell $cell Cell to bind value to
      * @param mixed $value Value to bind in cell
      *
      * @return bool
      */
-    public function bindValue(\PhpOffice\PhpSpreadsheet\Cell $cell, $value = null);
+    public function bindValue(Cell $cell, $value = null);
 }
diff --git a/src/PhpSpreadsheet/Chart/DataSeries.php b/src/PhpSpreadsheet/Chart/DataSeries.php
index 092736a6..63be0d41 100644
--- a/src/PhpSpreadsheet/Chart/DataSeries.php
+++ b/src/PhpSpreadsheet/Chart/DataSeries.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Chart;
 
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -388,7 +390,7 @@ class DataSeries
         return $this;
     }
 
-    public function refresh(\PhpOffice\PhpSpreadsheet\Worksheet $worksheet)
+    public function refresh(Worksheet $worksheet)
     {
         foreach ($this->plotValues as $plotValues) {
             if ($plotValues !== null) {
diff --git a/src/PhpSpreadsheet/Chart/DataSeriesValues.php b/src/PhpSpreadsheet/Chart/DataSeriesValues.php
index 82813400..4fee7c28 100644
--- a/src/PhpSpreadsheet/Chart/DataSeriesValues.php
+++ b/src/PhpSpreadsheet/Chart/DataSeriesValues.php
@@ -2,6 +2,11 @@
 
 namespace PhpOffice\PhpSpreadsheet\Chart;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -111,9 +116,9 @@ class DataSeriesValues
      *
      * @param string $dataType Datatype of this data series
      *                                Typical values are:
-     *                                    \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues::DATASERIES_TYPE_STRING
+     *                                    DataSeriesValues::DATASERIES_TYPE_STRING
      *                                        Normally used for axis point values
-     *                                    \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues::DATASERIES_TYPE_NUMBER
+     *                                    DataSeriesValues::DATASERIES_TYPE_NUMBER
      *                                        Normally used for chart data values
      *
      * @throws Exception
@@ -277,17 +282,17 @@ class DataSeriesValues
      */
     public function setDataValues($dataValues)
     {
-        $this->dataValues = \PhpOffice\PhpSpreadsheet\Calculation\Functions::flattenArray($dataValues);
+        $this->dataValues = Functions::flattenArray($dataValues);
         $this->pointCount = count($dataValues);
 
         return $this;
     }
 
-    public function refresh(\PhpOffice\PhpSpreadsheet\Worksheet $worksheet, $flatten = true)
+    public function refresh(Worksheet $worksheet, $flatten = true)
     {
         if ($this->dataSource !== null) {
-            $calcEngine = \PhpOffice\PhpSpreadsheet\Calculation::getInstance($worksheet->getParent());
-            $newDataValues = \PhpOffice\PhpSpreadsheet\Calculation::unwrapResult(
+            $calcEngine = Calculation::getInstance($worksheet->getParent());
+            $newDataValues = Calculation::unwrapResult(
                 $calcEngine->_calculateFormulaValue(
                     '=' . $this->dataSource,
                     null,
@@ -295,7 +300,7 @@ class DataSeriesValues
                 )
             );
             if ($flatten) {
-                $this->dataValues = \PhpOffice\PhpSpreadsheet\Calculation\Functions::flattenArray($newDataValues);
+                $this->dataValues = Functions::flattenArray($newDataValues);
                 foreach ($this->dataValues as &$dataValue) {
                     if ((!empty($dataValue)) && ($dataValue[0] == '#')) {
                         $dataValue = 0.0;
@@ -308,9 +313,9 @@ class DataSeriesValues
                     list(, $cellRange) = $cellRange;
                 }
 
-                $dimensions = \PhpOffice\PhpSpreadsheet\Cell::rangeDimension(str_replace('$', '', $cellRange));
+                $dimensions = Cell::rangeDimension(str_replace('$', '', $cellRange));
                 if (($dimensions[0] == 1) || ($dimensions[1] == 1)) {
-                    $this->dataValues = \PhpOffice\PhpSpreadsheet\Calculation\Functions::flattenArray($newDataValues);
+                    $this->dataValues = Functions::flattenArray($newDataValues);
                 } else {
                     $newArray = array_values(array_shift($newDataValues));
                     foreach ($newArray as $i => $newDataSet) {
diff --git a/src/PhpSpreadsheet/Chart/Exception.php b/src/PhpSpreadsheet/Chart/Exception.php
index 57562b73..9c19cfd7 100644
--- a/src/PhpSpreadsheet/Chart/Exception.php
+++ b/src/PhpSpreadsheet/Chart/Exception.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Chart;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +26,7 @@ namespace PhpOffice\PhpSpreadsheet\Chart;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Exception extends \PhpOffice\PhpSpreadsheet\Exception
+class Exception extends PhpSpreadsheetException
 {
     /**
      * Error handler callback.
diff --git a/src/PhpSpreadsheet/Chart/PlotArea.php b/src/PhpSpreadsheet/Chart/PlotArea.php
index 5c16db84..0dd12cd4 100644
--- a/src/PhpSpreadsheet/Chart/PlotArea.php
+++ b/src/PhpSpreadsheet/Chart/PlotArea.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Chart;
 
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -124,7 +126,7 @@ class PlotArea
         return $this;
     }
 
-    public function refresh(\PhpOffice\PhpSpreadsheet\Worksheet $worksheet)
+    public function refresh(Worksheet $worksheet)
     {
         foreach ($this->plotSeries as $plotSeries) {
             $plotSeries->refresh($worksheet);
diff --git a/src/PhpSpreadsheet/Chart/Renderer/JpGraph.php b/src/PhpSpreadsheet/Chart/Renderer/JpGraph.php
index 834d06d8..53883f45 100644
--- a/src/PhpSpreadsheet/Chart/Renderer/JpGraph.php
+++ b/src/PhpSpreadsheet/Chart/Renderer/JpGraph.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Chart\Renderer;
 
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\Settings;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -105,7 +108,7 @@ class JpGraph
             } else {
                 //    Format labels according to any formatting code
                 if (!is_null($datasetLabelFormatCode)) {
-                    $datasetLabels[$i] = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString($datasetLabel, $datasetLabelFormatCode);
+                    $datasetLabels[$i] = NumberFormat::toFormattedString($datasetLabel, $datasetLabelFormatCode);
                 }
             }
             ++$testCurrentIndex;
@@ -542,7 +545,7 @@ class JpGraph
 
     private function renderAreaChart($groupCount, $dimensions = '2d')
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_line.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_line.php';
 
         $this->renderCartesianPlotArea();
 
@@ -553,7 +556,7 @@ class JpGraph
 
     private function renderLineChart($groupCount, $dimensions = '2d')
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_line.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_line.php';
 
         $this->renderCartesianPlotArea();
 
@@ -564,7 +567,7 @@ class JpGraph
 
     private function renderBarChart($groupCount, $dimensions = '2d')
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_bar.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_bar.php';
 
         $this->renderCartesianPlotArea();
 
@@ -575,9 +578,9 @@ class JpGraph
 
     private function renderScatterChart($groupCount)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_scatter.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_regstat.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_line.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_scatter.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_regstat.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_line.php';
 
         $this->renderCartesianPlotArea('linlin');
 
@@ -588,7 +591,7 @@ class JpGraph
 
     private function renderBubbleChart($groupCount)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_scatter.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_scatter.php';
 
         $this->renderCartesianPlotArea('linlin');
 
@@ -599,9 +602,9 @@ class JpGraph
 
     private function renderPieChart($groupCount, $dimensions = '2d', $doughnut = false, $multiplePlots = false)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_pie.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_pie.php';
         if ($dimensions == '3d') {
-            require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_pie3d.php';
+            require_once Settings::getChartRendererPath() . 'jpgraph_pie3d.php';
         }
 
         $this->renderPiePlotArea($doughnut);
@@ -675,7 +678,7 @@ class JpGraph
 
     private function renderRadarChart($groupCount)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_radar.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_radar.php';
 
         $this->renderRadarPlotArea();
 
@@ -686,7 +689,7 @@ class JpGraph
 
     private function renderStockChart($groupCount)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_stock.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_stock.php';
 
         $this->renderCartesianPlotArea('intint');
 
@@ -697,7 +700,7 @@ class JpGraph
 
     private function renderContourChart($groupCount, $dimensions)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_contour.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_contour.php';
 
         $this->renderCartesianPlotArea('intint');
 
@@ -708,11 +711,11 @@ class JpGraph
 
     private function renderCombinationChart($groupCount, $dimensions, $outputDestination)
     {
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_line.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_bar.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_scatter.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_regstat.php';
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . 'jpgraph_line.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_line.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_bar.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_scatter.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_regstat.php';
+        require_once Settings::getChartRendererPath() . 'jpgraph_line.php';
 
         $this->renderCartesianPlotArea();
 
@@ -848,11 +851,11 @@ class JpGraph
     /**
      * Create a new jpgraph.
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Chart $chart)
+    public function __construct(Chart $chart)
     {
         $this->graph = null;
         $this->chart = $chart;
 
-        require_once \PhpOffice\PhpSpreadsheet\Settings::getChartRendererPath() . '/jpgraph.php';
+        require_once Settings::getChartRendererPath() . '/jpgraph.php';
     }
 }
diff --git a/src/PhpSpreadsheet/Collection/Cells.php b/src/PhpSpreadsheet/Collection/Cells.php
index 137b6f90..daef9040 100644
--- a/src/PhpSpreadsheet/Collection/Cells.php
+++ b/src/PhpSpreadsheet/Collection/Cells.php
@@ -3,6 +3,7 @@
 namespace PhpOffice\PhpSpreadsheet\Collection;
 
 use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use Psr\SimpleCache\CacheInterface;
 
@@ -124,7 +125,7 @@ class Cells
      *
      * @param Cell $cell Cell to update
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Cell
      */
@@ -138,7 +139,7 @@ class Cells
      *
      * @param string $pCoord Coordinate of the cell to delete
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function delete($pCoord)
     {
@@ -342,7 +343,7 @@ class Cells
         $stored = $newCollection->cache->setMultiple($newValues);
         if (!$stored) {
             $newCollection->__destruct();
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Failed to copy cells in cache');
+            throw new PhpSpreadsheetException('Failed to copy cells in cache');
         }
 
         return $newCollection;
@@ -382,7 +383,7 @@ class Cells
      * Store cell data in cache for the current cell object if it's "dirty",
      * and the 'nullify' the current cell object.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     private function storeCurrentCell()
     {
@@ -392,7 +393,7 @@ class Cells
             $stored = $this->cache->set($this->cachePrefix . $this->currentCoordinate, $this->currentCell);
             if (!$stored) {
                 $this->__destruct();
-                throw new \PhpOffice\PhpSpreadsheet\Exception("Failed to store cell {$this->currentCoordinate} in cache");
+                throw new PhpSpreadsheetException("Failed to store cell {$this->currentCoordinate} in cache");
             }
             $this->currentCellIsDirty = false;
         }
@@ -407,7 +408,7 @@ class Cells
      * @param string $pCoord Coordinate of the cell to update
      * @param Cell $cell Cell to update
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Cell
      */
@@ -430,7 +431,7 @@ class Cells
      *
      * @param string $pCoord Coordinate of the cell
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Cell Cell that was found, or null if not found
      */
@@ -449,7 +450,7 @@ class Cells
         // Check if the entry that has been requested actually exists
         $cell = $this->cache->get($this->cachePrefix . $pCoord);
         if ($cell === null) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Cell entry {$pCoord} no longer exists in cache. This probably means that the cache was cleared by someone else.");
+            throw new PhpSpreadsheetException("Cell entry {$pCoord} no longer exists in cache. This probably means that the cache was cleared by someone else.");
         }
 
         // Set current entry to the requested entry
diff --git a/src/PhpSpreadsheet/Collection/Memory.php b/src/PhpSpreadsheet/Collection/Memory.php
index 966b84ba..a32551b0 100644
--- a/src/PhpSpreadsheet/Collection/Memory.php
+++ b/src/PhpSpreadsheet/Collection/Memory.php
@@ -2,13 +2,15 @@
 
 namespace PhpOffice\PhpSpreadsheet\Collection;
 
+use Psr\SimpleCache\CacheInterface;
+
 /**
  * This is the default implementation for in-memory cell collection.
  *
  * Alternatives implementation should leverage off-memory, non-volatile storage
  * to reduce overall memory usage.
  */
-class Memory implements \Psr\SimpleCache\CacheInterface
+class Memory implements CacheInterface
 {
     private $cache = [];
 
diff --git a/src/PhpSpreadsheet/Document/Security.php b/src/PhpSpreadsheet/Document/Security.php
index 6bb99b97..0175dcc4 100644
--- a/src/PhpSpreadsheet/Document/Security.php
+++ b/src/PhpSpreadsheet/Document/Security.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Document;
 
+use PhpOffice\PhpSpreadsheet\Shared\PasswordHasher;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -173,7 +175,7 @@ class Security
     public function setRevisionsPassword($pValue, $pAlreadyHashed = false)
     {
         if (!$pAlreadyHashed) {
-            $pValue = \PhpOffice\PhpSpreadsheet\Shared\PasswordHasher::hashPassword($pValue);
+            $pValue = PasswordHasher::hashPassword($pValue);
         }
         $this->revisionsPassword = $pValue;
 
@@ -201,7 +203,7 @@ class Security
     public function setWorkbookPassword($pValue, $pAlreadyHashed = false)
     {
         if (!$pAlreadyHashed) {
-            $pValue = \PhpOffice\PhpSpreadsheet\Shared\PasswordHasher::hashPassword($pValue);
+            $pValue = PasswordHasher::hashPassword($pValue);
         }
         $this->workbookPassword = $pValue;
 
diff --git a/src/PhpSpreadsheet/Helper/Html.php b/src/PhpSpreadsheet/Helper/Html.php
index 67b3c481..a968a931 100644
--- a/src/PhpSpreadsheet/Helper/Html.php
+++ b/src/PhpSpreadsheet/Helper/Html.php
@@ -6,6 +6,9 @@ use DOMDocument;
 use DOMElement;
 use DOMNode;
 use DOMText;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Font;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -625,7 +628,7 @@ class Html
         //    Discard excess white space
         $dom->preserveWhiteSpace = false;
 
-        $this->richTextObject = new \PhpOffice\PhpSpreadsheet\RichText();
+        $this->richTextObject = new RichText();
         $this->parseElements($dom);
 
         // Clean any further spurious whitespace
@@ -663,7 +666,7 @@ class Html
             $richtextRun->getFont()->setSize($this->size);
         }
         if ($this->color) {
-            $richtextRun->getFont()->setColor(new \PhpOffice\PhpSpreadsheet\Style\Color('ff' . $this->color));
+            $richtextRun->getFont()->setColor(new Color('ff' . $this->color));
         }
         if ($this->bold) {
             $richtextRun->getFont()->setBold(true);
@@ -672,7 +675,7 @@ class Html
             $richtextRun->getFont()->setItalic(true);
         }
         if ($this->underline) {
-            $richtextRun->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE);
+            $richtextRun->getFont()->setUnderline(Font::UNDERLINE_SINGLE);
         }
         if ($this->superscript) {
             $richtextRun->getFont()->setSuperScript(true);
diff --git a/src/PhpSpreadsheet/Helper/Sample.php b/src/PhpSpreadsheet/Helper/Sample.php
index e6cf1530..c538fe95 100644
--- a/src/PhpSpreadsheet/Helper/Sample.php
+++ b/src/PhpSpreadsheet/Helper/Sample.php
@@ -4,6 +4,8 @@ namespace PhpOffice\PhpSpreadsheet\Helper;
 
 use PhpOffice\PhpSpreadsheet\IOFactory;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\IWriter;
+use ReflectionClass;
 
 /**
  * Helper class to be used in sample code.
@@ -164,15 +166,17 @@ class Sample
     /**
      * Log a line about the write operation.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Writer\IWriter $writer
+     * @param IWriter $writer
      * @param string $path
      * @param float $callStartTime
+     *
+     * @throws \ReflectionException
      */
-    public function logWrite(\PhpOffice\PhpSpreadsheet\Writer\IWriter $writer, $path, $callStartTime)
+    public function logWrite(IWriter $writer, $path, $callStartTime)
     {
         $callEndTime = microtime(true);
         $callTime = $callEndTime - $callStartTime;
-        $reflection = new \ReflectionClass($writer);
+        $reflection = new ReflectionClass($writer);
         $format = $reflection->getShortName();
         $message = "Write {$format} format to <code>{$path}</code>  in " . sprintf('%.4f', $callTime) . ' seconds';
 
diff --git a/src/PhpSpreadsheet/Reader/Csv.php b/src/PhpSpreadsheet/Reader/Csv.php
index c0d064b7..7924e37e 100644
--- a/src/PhpSpreadsheet/Reader/Csv.php
+++ b/src/PhpSpreadsheet/Reader/Csv.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 /**
@@ -266,7 +268,7 @@ class Csv extends BaseReader implements IReader
             $worksheetInfo[0]['lastColumnIndex'] = max($worksheetInfo[0]['lastColumnIndex'], count($rowData) - 1);
         }
 
-        $worksheetInfo[0]['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex']);
+        $worksheetInfo[0]['lastColumnLetter'] = Cell::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex']);
         $worksheetInfo[0]['totalColumns'] = $worksheetInfo[0]['lastColumnIndex'] + 1;
 
         // Close file
@@ -282,12 +284,12 @@ class Csv extends BaseReader implements IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename)
     {
         // Create new Spreadsheet
-        $spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+        $spreadsheet = new Spreadsheet();
 
         // Load into this instance
         return $this->loadIntoExisting($pFilename, $spreadsheet);
@@ -339,7 +341,7 @@ class Csv extends BaseReader implements IReader
                 if ($rowDatum != '' && $this->readFilter->readCell($columnLetter, $currentRow)) {
                     // Convert encoding if necessary
                     if ($this->inputEncoding !== 'UTF-8') {
-                        $rowDatum = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($rowDatum, 'UTF-8', $this->inputEncoding);
+                        $rowDatum = StringHelper::convertEncoding($rowDatum, 'UTF-8', $this->inputEncoding);
                     }
 
                     // Set cell value
diff --git a/src/PhpSpreadsheet/Reader/Exception.php b/src/PhpSpreadsheet/Reader/Exception.php
index 167ab4ac..5f2ce05d 100644
--- a/src/PhpSpreadsheet/Reader/Exception.php
+++ b/src/PhpSpreadsheet/Reader/Exception.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +26,7 @@ namespace PhpOffice\PhpSpreadsheet\Reader;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Exception extends \PhpOffice\PhpSpreadsheet\Exception
+class Exception extends PhpSpreadsheetException
 {
     /**
      * Error handler callback.
diff --git a/src/PhpSpreadsheet/Reader/Gnumeric.php b/src/PhpSpreadsheet/Reader/Gnumeric.php
index c6418704..313fcf00 100644
--- a/src/PhpSpreadsheet/Reader/Gnumeric.php
+++ b/src/PhpSpreadsheet/Reader/Gnumeric.php
@@ -3,8 +3,20 @@
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
 use DateTimeZone;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\NamedRange;
+use PhpOffice\PhpSpreadsheet\ReferenceHelper;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Shared\File;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Borders;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use XMLReader;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -52,7 +64,7 @@ class Gnumeric extends BaseReader implements IReader
     public function __construct()
     {
         $this->readFilter = new DefaultReadFilter();
-        $this->referenceHelper = \PhpOffice\PhpSpreadsheet\ReferenceHelper::getInstance();
+        $this->referenceHelper = ReferenceHelper::getInstance();
     }
 
     /**
@@ -97,7 +109,7 @@ class Gnumeric extends BaseReader implements IReader
         File::assertFile($pFilename);
 
         $xml = new XMLReader();
-        $xml->xml($this->securityScanFile('compress.zlib://' . realpath($pFilename)), null, \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions());
+        $xml->xml($this->securityScanFile('compress.zlib://' . realpath($pFilename)), null, Settings::getLibXmlLoaderOptions());
         $xml->setParserProperty(2, true);
 
         $worksheetNames = [];
@@ -126,7 +138,7 @@ class Gnumeric extends BaseReader implements IReader
         File::assertFile($pFilename);
 
         $xml = new XMLReader();
-        $xml->xml($this->securityScanFile('compress.zlib://' . realpath($pFilename)), null, \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions());
+        $xml->xml($this->securityScanFile('compress.zlib://' . realpath($pFilename)), null, Settings::getLibXmlLoaderOptions());
         $xml->setParserProperty(2, true);
 
         $worksheetInfo = [];
@@ -154,7 +166,7 @@ class Gnumeric extends BaseReader implements IReader
                         break;
                     }
                 }
-                $tmpInfo['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
+                $tmpInfo['lastColumnLetter'] = Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
                 $worksheetInfo[] = $tmpInfo;
             }
         }
@@ -216,7 +228,7 @@ class Gnumeric extends BaseReader implements IReader
 
         $gFileData = $this->gzfileGetContents($pFilename);
 
-        $xml = simplexml_load_string($this->securityScan($gFileData), 'SimpleXMLElement', \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions());
+        $xml = simplexml_load_string($this->securityScan($gFileData), 'SimpleXMLElement', Settings::getLibXmlLoaderOptions());
         $namespacesMeta = $xml->getNamespaces(true);
 
         $gnmXML = $xml->children($namespacesMeta['gnm']);
@@ -387,7 +399,7 @@ class Gnumeric extends BaseReader implements IReader
                     $maxCol = $column;
                 }
 
-                $column = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+                $column = Cell::stringFromColumnIndex($column);
 
                 // Read cell?
                 if ($this->getReadFilter() !== null) {
@@ -398,7 +410,7 @@ class Gnumeric extends BaseReader implements IReader
 
                 $ValueType = $cellAttributes->ValueType;
                 $ExprID = (string) $cellAttributes->ExprID;
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA;
+                $type = Cell\DataType::TYPE_FORMULA;
                 if ($ExprID > '') {
                     if (((string) $cell) > '') {
                         $this->expressions[$ExprID] = [
@@ -417,27 +429,27 @@ class Gnumeric extends BaseReader implements IReader
                             $worksheetName
                         );
                     }
-                    $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA;
+                    $type = Cell\DataType::TYPE_FORMULA;
                 } else {
                     switch ($ValueType) {
                         case '10':        //    NULL
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NULL;
+                            $type = Cell\DataType::TYPE_NULL;
                             break;
                         case '20':        //    Boolean
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_BOOL;
+                            $type = Cell\DataType::TYPE_BOOL;
                             $cell = ($cell == 'TRUE') ? true : false;
                             break;
                         case '30':        //    Integer
                             $cell = (int) $cell;
                             // Excel 2007+ doesn't differentiate between integer and float, so set the value and dropthru to the next (numeric) case
                         case '40':        //    Float
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC;
+                            $type = Cell\DataType::TYPE_NUMERIC;
                             break;
                         case '50':        //    Error
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_ERROR;
+                            $type = Cell\DataType::TYPE_ERROR;
                             break;
                         case '60':        //    String
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING;
+                            $type = Cell\DataType::TYPE_STRING;
                             break;
                         case '70':        //    Cell Range
                         case '80':        //    Array
@@ -459,11 +471,11 @@ class Gnumeric extends BaseReader implements IReader
                 $styleAttributes = $styleRegion->attributes();
                 if (($styleAttributes['startRow'] <= $maxRow) &&
                     ($styleAttributes['startCol'] <= $maxCol)) {
-                    $startColumn = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex((int) $styleAttributes['startCol']);
+                    $startColumn = Cell::stringFromColumnIndex((int) $styleAttributes['startCol']);
                     $startRow = $styleAttributes['startRow'] + 1;
 
                     $endColumn = ($styleAttributes['endCol'] > $maxCol) ? $maxCol : (int) $styleAttributes['endCol'];
-                    $endColumn = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($endColumn);
+                    $endColumn = Cell::stringFromColumnIndex($endColumn);
                     $endRow = ($styleAttributes['endRow'] > $maxRow) ? $maxRow : $styleAttributes['endRow'];
                     $endRow += 1;
                     $cellRange = $startColumn . $startRow . ':' . $endColumn . $endRow;
@@ -472,45 +484,45 @@ class Gnumeric extends BaseReader implements IReader
 
                     //    We still set the number format mask for date/time values, even if readDataOnly is true
                     if ((!$this->readDataOnly) ||
-                        (\PhpOffice\PhpSpreadsheet\Shared\Date::isDateTimeFormatCode((string) $styleAttributes['Format']))) {
+                        (Date::isDateTimeFormatCode((string) $styleAttributes['Format']))) {
                         $styleArray = [];
                         $styleArray['numberformat']['code'] = (string) $styleAttributes['Format'];
                         //    If readDataOnly is false, we set all formatting information
                         if (!$this->readDataOnly) {
                             switch ($styleAttributes['HAlign']) {
                                 case '1':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_GENERAL;
                                     break;
                                 case '2':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_LEFT;
                                     break;
                                 case '4':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_RIGHT;
                                     break;
                                 case '8':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_CENTER;
                                     break;
                                 case '16':
                                 case '64':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_CENTER_CONTINUOUS;
                                     break;
                                 case '32':
-                                    $styleArray['alignment']['horizontal'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY;
+                                    $styleArray['alignment']['horizontal'] = Alignment::HORIZONTAL_JUSTIFY;
                                     break;
                             }
 
                             switch ($styleAttributes['VAlign']) {
                                 case '1':
-                                    $styleArray['alignment']['vertical'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP;
+                                    $styleArray['alignment']['vertical'] = Alignment::VERTICAL_TOP;
                                     break;
                                 case '2':
-                                    $styleArray['alignment']['vertical'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM;
+                                    $styleArray['alignment']['vertical'] = Alignment::VERTICAL_BOTTOM;
                                     break;
                                 case '4':
-                                    $styleArray['alignment']['vertical'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER;
+                                    $styleArray['alignment']['vertical'] = Alignment::VERTICAL_CENTER;
                                     break;
                                 case '8':
-                                    $styleArray['alignment']['vertical'] = \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY;
+                                    $styleArray['alignment']['vertical'] = Alignment::VERTICAL_JUSTIFY;
                                     break;
                             }
 
@@ -528,64 +540,64 @@ class Gnumeric extends BaseReader implements IReader
                                 $styleArray['fill']['endcolor']['rgb'] = $RGB2;
                                 switch ($shade) {
                                     case '1':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID;
+                                        $styleArray['fill']['type'] = Fill::FILL_SOLID;
                                         break;
                                     case '2':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR;
+                                        $styleArray['fill']['type'] = Fill::FILL_GRADIENT_LINEAR;
                                         break;
                                     case '3':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_PATH;
+                                        $styleArray['fill']['type'] = Fill::FILL_GRADIENT_PATH;
                                         break;
                                     case '4':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKDOWN;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKDOWN;
                                         break;
                                     case '5':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRAY;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKGRAY;
                                         break;
                                     case '6':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRID;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKGRID;
                                         break;
                                     case '7':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKHORIZONTAL;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKHORIZONTAL;
                                         break;
                                     case '8':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKTRELLIS;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKTRELLIS;
                                         break;
                                     case '9':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKUP;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKUP;
                                         break;
                                     case '10':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKVERTICAL;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_DARKVERTICAL;
                                         break;
                                     case '11':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY0625;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_GRAY0625;
                                         break;
                                     case '12':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY125;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_GRAY125;
                                         break;
                                     case '13':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTDOWN;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTDOWN;
                                         break;
                                     case '14':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRAY;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTGRAY;
                                         break;
                                     case '15':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRID;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTGRID;
                                         break;
                                     case '16':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTHORIZONTAL;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTHORIZONTAL;
                                         break;
                                     case '17':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTTRELLIS;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTTRELLIS;
                                         break;
                                     case '18':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTUP;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTUP;
                                         break;
                                     case '19':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTVERTICAL;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_LIGHTVERTICAL;
                                         break;
                                     case '20':
-                                        $styleArray['fill']['type'] = \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_MEDIUMGRAY;
+                                        $styleArray['fill']['type'] = Fill::FILL_PATTERN_MEDIUMGRAY;
                                         break;
                                 }
                             }
@@ -598,19 +610,19 @@ class Gnumeric extends BaseReader implements IReader
                             $styleArray['font']['strike'] = ($fontAttributes['StrikeThrough'] == '1') ? true : false;
                             switch ($fontAttributes['Underline']) {
                                 case '1':
-                                    $styleArray['font']['underline'] = \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE;
+                                    $styleArray['font']['underline'] = Font::UNDERLINE_SINGLE;
                                     break;
                                 case '2':
-                                    $styleArray['font']['underline'] = \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLE;
+                                    $styleArray['font']['underline'] = Font::UNDERLINE_DOUBLE;
                                     break;
                                 case '3':
-                                    $styleArray['font']['underline'] = \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLEACCOUNTING;
+                                    $styleArray['font']['underline'] = Font::UNDERLINE_SINGLEACCOUNTING;
                                     break;
                                 case '4':
-                                    $styleArray['font']['underline'] = \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLEACCOUNTING;
+                                    $styleArray['font']['underline'] = Font::UNDERLINE_DOUBLEACCOUNTING;
                                     break;
                                 default:
-                                    $styleArray['font']['underline'] = \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_NONE;
+                                    $styleArray['font']['underline'] = Font::UNDERLINE_NONE;
                                     break;
                             }
                             switch ($fontAttributes['Script']) {
@@ -637,13 +649,13 @@ class Gnumeric extends BaseReader implements IReader
                                 }
                                 if ((isset($styleRegion->Style->StyleBorder->Diagonal)) && (isset($styleRegion->Style->StyleBorder->{'Rev-Diagonal'}))) {
                                     $styleArray['borders']['diagonal'] = self::parseBorderAttributes($styleRegion->Style->StyleBorder->Diagonal->attributes());
-                                    $styleArray['borders']['diagonaldirection'] = \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_BOTH;
+                                    $styleArray['borders']['diagonaldirection'] = Borders::DIAGONAL_BOTH;
                                 } elseif (isset($styleRegion->Style->StyleBorder->Diagonal)) {
                                     $styleArray['borders']['diagonal'] = self::parseBorderAttributes($styleRegion->Style->StyleBorder->Diagonal->attributes());
-                                    $styleArray['borders']['diagonaldirection'] = \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_UP;
+                                    $styleArray['borders']['diagonaldirection'] = Borders::DIAGONAL_UP;
                                 } elseif (isset($styleRegion->Style->StyleBorder->{'Rev-Diagonal'})) {
                                     $styleArray['borders']['diagonal'] = self::parseBorderAttributes($styleRegion->Style->StyleBorder->{'Rev-Diagonal'}->attributes());
-                                    $styleArray['borders']['diagonaldirection'] = \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_DOWN;
+                                    $styleArray['borders']['diagonaldirection'] = Borders::DIAGONAL_DOWN;
                                 }
                             }
                             if (isset($styleRegion->Style->HyperLink)) {
@@ -668,19 +680,19 @@ class Gnumeric extends BaseReader implements IReader
                     $hidden = ((isset($columnAttributes['Hidden'])) && ($columnAttributes['Hidden'] == '1')) ? true : false;
                     $columnCount = (isset($columnAttributes['Count'])) ? $columnAttributes['Count'] : 1;
                     while ($c < $column) {
-                        $spreadsheet->getActiveSheet()->getColumnDimension(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c))->setWidth($defaultWidth);
+                        $spreadsheet->getActiveSheet()->getColumnDimension(Cell::stringFromColumnIndex($c))->setWidth($defaultWidth);
                         ++$c;
                     }
                     while (($c < ($column + $columnCount)) && ($c <= $maxCol)) {
-                        $spreadsheet->getActiveSheet()->getColumnDimension(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c))->setWidth($columnWidth);
+                        $spreadsheet->getActiveSheet()->getColumnDimension(Cell::stringFromColumnIndex($c))->setWidth($columnWidth);
                         if ($hidden) {
-                            $spreadsheet->getActiveSheet()->getColumnDimension(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c))->setVisible(false);
+                            $spreadsheet->getActiveSheet()->getColumnDimension(Cell::stringFromColumnIndex($c))->setVisible(false);
                         }
                         ++$c;
                     }
                 }
                 while ($c <= $maxCol) {
-                    $spreadsheet->getActiveSheet()->getColumnDimension(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c))->setWidth($defaultWidth);
+                    $spreadsheet->getActiveSheet()->getColumnDimension(Cell::stringFromColumnIndex($c))->setWidth($defaultWidth);
                     ++$c;
                 }
             }
@@ -740,7 +752,7 @@ class Gnumeric extends BaseReader implements IReader
                 $range[0] = trim($range[0], "'");
                 if ($worksheet = $spreadsheet->getSheetByName($range[0])) {
                     $extractedRange = str_replace('$', '', $range[1]);
-                    $spreadsheet->addNamedRange(new \PhpOffice\PhpSpreadsheet\NamedRange($name, $worksheet, $extractedRange));
+                    $spreadsheet->addNamedRange(new NamedRange($name, $worksheet, $extractedRange));
                 }
             }
         }
@@ -758,46 +770,46 @@ class Gnumeric extends BaseReader implements IReader
 
         switch ($borderAttributes['Style']) {
             case '0':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE;
+                $styleArray['style'] = Border::BORDER_NONE;
                 break;
             case '1':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                $styleArray['style'] = Border::BORDER_THIN;
                 break;
             case '2':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM;
+                $styleArray['style'] = Border::BORDER_MEDIUM;
                 break;
             case '3':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT;
+                $styleArray['style'] = Border::BORDER_SLANTDASHDOT;
                 break;
             case '4':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED;
+                $styleArray['style'] = Border::BORDER_DASHED;
                 break;
             case '5':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK;
+                $styleArray['style'] = Border::BORDER_THICK;
                 break;
             case '6':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE;
+                $styleArray['style'] = Border::BORDER_DOUBLE;
                 break;
             case '7':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED;
+                $styleArray['style'] = Border::BORDER_DOTTED;
                 break;
             case '8':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED;
+                $styleArray['style'] = Border::BORDER_MEDIUMDASHED;
                 break;
             case '9':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT;
+                $styleArray['style'] = Border::BORDER_DASHDOT;
                 break;
             case '10':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT;
+                $styleArray['style'] = Border::BORDER_MEDIUMDASHDOT;
                 break;
             case '11':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT;
+                $styleArray['style'] = Border::BORDER_DASHDOTDOT;
                 break;
             case '12':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT;
+                $styleArray['style'] = Border::BORDER_MEDIUMDASHDOTDOT;
                 break;
             case '13':
-                $styleArray['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT;
+                $styleArray['style'] = Border::BORDER_MEDIUMDASHDOTDOT;
                 break;
         }
 
@@ -806,7 +818,7 @@ class Gnumeric extends BaseReader implements IReader
 
     private function parseRichText($is)
     {
-        $value = new \PhpOffice\PhpSpreadsheet\RichText();
+        $value = new RichText();
         $value->createText($is);
 
         return $value;
diff --git a/src/PhpSpreadsheet/Reader/Html.php b/src/PhpSpreadsheet/Reader/Html.php
index 2f0aa473..4db753b5 100644
--- a/src/PhpSpreadsheet/Reader/Html.php
+++ b/src/PhpSpreadsheet/Reader/Html.php
@@ -6,7 +6,12 @@ use DOMDocument;
 use DOMElement;
 use DOMNode;
 use DOMText;
+use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Worksheet;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -98,16 +103,16 @@ class Html extends BaseReader implements IReader
             'font' => [
                 'underline' => true,
                 'color' => [
-                    'argb' => \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLUE,
+                    'argb' => Color::COLOR_BLUE,
                 ],
             ],
         ], //    Blue underlined
         'hr' => [
             'borders' => [
                 'bottom' => [
-                    'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN,
+                    'style' => Border::BORDER_THIN,
                     'color' => [
-                        \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK,
+                        Color::COLOR_BLACK,
                     ],
                 ],
             ],
@@ -276,12 +281,12 @@ class Html extends BaseReader implements IReader
 
     /**
      * @param DOMNode $element
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet
+     * @param Worksheet $sheet
      * @param int $row
      * @param string $column
      * @param string $cellContent
      */
-    protected function processDomElement(DOMNode $element, \PhpOffice\PhpSpreadsheet\Worksheet $sheet, &$row, &$column, &$cellContent)
+    protected function processDomElement(DOMNode $element, Worksheet $sheet, &$row, &$column, &$cellContent)
     {
         foreach ($element->childNodes as $child) {
             if ($child instanceof DOMText) {
@@ -450,7 +455,7 @@ class Html extends BaseReader implements IReader
                                 ++$columnTo;
                             }
                             $range = $column . $row . ':' . $columnTo . ($row + $attributeArray['rowspan'] - 1);
-                            foreach (\PhpOffice\PhpSpreadsheet\Cell::extractAllCellReferencesInRange($range) as $value) {
+                            foreach (Cell::extractAllCellReferencesInRange($range) as $value) {
                                 $this->rowspan[$value] = true;
                             }
                             $sheet->mergeCells($range);
@@ -458,7 +463,7 @@ class Html extends BaseReader implements IReader
                         } elseif (isset($attributeArray['rowspan'])) {
                             //create merging rowspan
                             $range = $column . $row . ':' . $column . ($row + $attributeArray['rowspan'] - 1);
-                            foreach (\PhpOffice\PhpSpreadsheet\Cell::extractAllCellReferencesInRange($range) as $value) {
+                            foreach (Cell::extractAllCellReferencesInRange($range) as $value) {
                                 $this->rowspan[$value] = true;
                             }
                             $sheet->mergeCells($range);
@@ -474,7 +479,7 @@ class Html extends BaseReader implements IReader
                             $sheet->getStyle($column . $row)->applyFromArray(
                                 [
                                     'fill' => [
-                                        'type' => PHPExcel_Style_Fill::FILL_SOLID,
+                                        'type' => Fill::FILL_SOLID,
                                         'color' => ['rgb' => $attributeArray['bgcolor']],
                                     ],
                                 ]
diff --git a/src/PhpSpreadsheet/Reader/IReader.php b/src/PhpSpreadsheet/Reader/IReader.php
index 7ef8d48b..3d4bfa99 100644
--- a/src/PhpSpreadsheet/Reader/IReader.php
+++ b/src/PhpSpreadsheet/Reader/IReader.php
@@ -42,7 +42,7 @@ interface IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename);
 }
diff --git a/src/PhpSpreadsheet/Reader/Ods.php b/src/PhpSpreadsheet/Reader/Ods.php
index 13f48ea4..e82d2d4e 100644
--- a/src/PhpSpreadsheet/Reader/Ods.php
+++ b/src/PhpSpreadsheet/Reader/Ods.php
@@ -5,9 +5,16 @@ namespace PhpOffice\PhpSpreadsheet\Reader;
 use DateTime;
 use DateTimeZone;
 use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Cell\DataType;
+use PhpOffice\PhpSpreadsheet\Document\Properties;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use XMLReader;
 use ZipArchive;
 
 /**
@@ -76,7 +83,7 @@ class Ods extends BaseReader implements IReader
                 $xml = simplexml_load_string(
                     $this->securityScan($zip->getFromName('META-INF/manifest.xml')),
                     'SimpleXMLElement',
-                    \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+                    Settings::getLibXmlLoaderOptions()
                 );
                 $namespacesContent = $xml->getNamespaces(true);
                 if (isset($namespacesContent['manifest'])) {
@@ -119,11 +126,11 @@ class Ods extends BaseReader implements IReader
 
         $worksheetNames = [];
 
-        $xml = new \XMLReader();
+        $xml = new XMLReader();
         $xml->xml(
             $this->securityScanFile('zip://' . realpath($pFilename) . '#content.xml'),
             null,
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $xml->setParserProperty(2, true);
 
@@ -140,12 +147,12 @@ class Ods extends BaseReader implements IReader
             }
             // Now read each node until we find our first table:table node
             while ($xml->read()) {
-                if ($xml->name == 'table:table' && $xml->nodeType == \XMLReader::ELEMENT) {
+                if ($xml->name == 'table:table' && $xml->nodeType == XMLReader::ELEMENT) {
                     // Loop through each table:table node reading the table:name attribute for each worksheet name
                     do {
                         $worksheetNames[] = $xml->getAttribute('table:name');
                         $xml->next();
-                    } while ($xml->name == 'table:table' && $xml->nodeType == \XMLReader::ELEMENT);
+                    } while ($xml->name == 'table:table' && $xml->nodeType == XMLReader::ELEMENT);
                 }
             }
         }
@@ -173,11 +180,11 @@ class Ods extends BaseReader implements IReader
             throw new Exception('Could not open ' . $pFilename . ' for reading! Error opening file.');
         }
 
-        $xml = new \XMLReader();
+        $xml = new XMLReader();
         $res = $xml->xml(
             $this->securityScanFile('zip://' . realpath($pFilename) . '#content.xml'),
             null,
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $xml->setParserProperty(2, true);
 
@@ -194,7 +201,7 @@ class Ods extends BaseReader implements IReader
             }
                 // Now read each node until we find our first table:table node
             while ($xml->read()) {
-                if ($xml->name == 'table:table' && $xml->nodeType == \XMLReader::ELEMENT) {
+                if ($xml->name == 'table:table' && $xml->nodeType == XMLReader::ELEMENT) {
                     $worksheetNames[] = $xml->getAttribute('table:name');
 
                     $tmpInfo = [
@@ -209,7 +216,7 @@ class Ods extends BaseReader implements IReader
                     $currCells = 0;
                     do {
                         $xml->read();
-                        if ($xml->name == 'table:table-row' && $xml->nodeType == \XMLReader::ELEMENT) {
+                        if ($xml->name == 'table:table-row' && $xml->nodeType == XMLReader::ELEMENT) {
                             $rowspan = $xml->getAttribute('table:number-rows-repeated');
                             $rowspan = empty($rowspan) ? 1 : $rowspan;
                             $tmpInfo['totalRows'] += $rowspan;
@@ -218,14 +225,14 @@ class Ods extends BaseReader implements IReader
                             // Step into the row
                             $xml->read();
                             do {
-                                if ($xml->name == 'table:table-cell' && $xml->nodeType == \XMLReader::ELEMENT) {
+                                if ($xml->name == 'table:table-cell' && $xml->nodeType == XMLReader::ELEMENT) {
                                     if (!$xml->isEmptyElement) {
                                         ++$currCells;
                                         $xml->next();
                                     } else {
                                         $xml->read();
                                     }
-                                } elseif ($xml->name == 'table:covered-table-cell' && $xml->nodeType == \XMLReader::ELEMENT) {
+                                } elseif ($xml->name == 'table:covered-table-cell' && $xml->nodeType == XMLReader::ELEMENT) {
                                     $mergeSize = $xml->getAttribute('table:number-columns-repeated');
                                     $currCells += $mergeSize;
                                     $xml->read();
@@ -236,7 +243,7 @@ class Ods extends BaseReader implements IReader
 
                     $tmpInfo['totalColumns'] = max($tmpInfo['totalColumns'], $currCells);
                     $tmpInfo['lastColumnIndex'] = $tmpInfo['totalColumns'] - 1;
-                    $tmpInfo['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
+                    $tmpInfo['lastColumnLetter'] = Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
                     $worksheetInfo[] = $tmpInfo;
                 }
             }
@@ -252,12 +259,12 @@ class Ods extends BaseReader implements IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename)
     {
         // Create new Spreadsheet
-        $spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+        $spreadsheet = new Spreadsheet();
 
         // Load into this instance
         return $this->loadIntoExisting($pFilename, $spreadsheet);
@@ -281,13 +288,13 @@ class Ods extends BaseReader implements IReader
      * Loads PhpSpreadsheet from file into PhpSpreadsheet instance.
      *
      * @param string $pFilename
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
-    public function loadIntoExisting($pFilename, \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function loadIntoExisting($pFilename, Spreadsheet $spreadsheet)
     {
         File::assertFile($pFilename);
 
@@ -306,7 +313,7 @@ class Ods extends BaseReader implements IReader
         $xml = simplexml_load_string(
             $this->securityScan($zip->getFromName('meta.xml')),
             'SimpleXMLElement',
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $namespacesMeta = $xml->getNamespaces(true);
 
@@ -359,26 +366,26 @@ class Ods extends BaseReader implements IReader
                         $docProps->setCreated($creationDate);
                         break;
                     case 'user-defined':
-                        $propertyValueType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_STRING;
+                        $propertyValueType = Properties::PROPERTY_TYPE_STRING;
                         foreach ($propertyValueAttributes as $key => $value) {
                             if ($key == 'name') {
                                 $propertyValueName = (string) $value;
                             } elseif ($key == 'value-type') {
                                 switch ($value) {
                                     case 'date':
-                                        $propertyValue = \PhpOffice\PhpSpreadsheet\Document\Properties::convertProperty($propertyValue, 'date');
-                                        $propertyValueType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_DATE;
+                                        $propertyValue = Properties::convertProperty($propertyValue, 'date');
+                                        $propertyValueType = Properties::PROPERTY_TYPE_DATE;
                                         break;
                                     case 'boolean':
-                                        $propertyValue = \PhpOffice\PhpSpreadsheet\Document\Properties::convertProperty($propertyValue, 'bool');
-                                        $propertyValueType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_BOOLEAN;
+                                        $propertyValue = Properties::convertProperty($propertyValue, 'bool');
+                                        $propertyValueType = Properties::PROPERTY_TYPE_BOOLEAN;
                                         break;
                                     case 'float':
-                                        $propertyValue = \PhpOffice\PhpSpreadsheet\Document\Properties::convertProperty($propertyValue, 'r4');
-                                        $propertyValueType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_FLOAT;
+                                        $propertyValue = Properties::convertProperty($propertyValue, 'r4');
+                                        $propertyValueType = Properties::PROPERTY_TYPE_FLOAT;
                                         break;
                                     default:
-                                        $propertyValueType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_STRING;
+                                        $propertyValueType = Properties::PROPERTY_TYPE_STRING;
                                 }
                             }
                         }
@@ -395,7 +402,7 @@ class Ods extends BaseReader implements IReader
         $dom = new \DOMDocument('1.01', 'UTF-8');
         $dom->loadXML(
             $this->securityScan($zip->getFromName('content.xml')),
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
 
         $officeNs = $dom->lookupNamespaceUri('office');
@@ -563,7 +570,7 @@ class Ods extends BaseReader implements IReader
                                             if (floor($dataValue) == $dataValue) {
                                                 $dataValue = (int) $dataValue;
                                             }
-                                            $formatting = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_PERCENTAGE_00;
+                                            $formatting = NumberFormat::FORMAT_PERCENTAGE_00;
                                             break;
                                         case 'currency':
                                             $type = DataType::TYPE_NUMERIC;
@@ -572,7 +579,7 @@ class Ods extends BaseReader implements IReader
                                             if (floor($dataValue) == $dataValue) {
                                                 $dataValue = (int) $dataValue;
                                             }
-                                            $formatting = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE;
+                                            $formatting = NumberFormat::FORMAT_CURRENCY_USD_SIMPLE;
                                             break;
                                         case 'float':
                                             $type = DataType::TYPE_NUMERIC;
@@ -597,7 +604,7 @@ class Ods extends BaseReader implements IReader
                                                 $dateObj->format('Y m d H i s')
                                             );
 
-                                            $dataValue = \PhpOffice\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
+                                            $dataValue = Date::formattedPHPToExcel(
                                                 $year,
                                                 $month,
                                                 $day,
@@ -607,11 +614,11 @@ class Ods extends BaseReader implements IReader
                                             );
 
                                             if ($dataValue != floor($dataValue)) {
-                                                $formatting = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX15
+                                                $formatting = NumberFormat::FORMAT_DATE_XLSX15
                                                     . ' '
-                                                    . \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME4;
+                                                    . NumberFormat::FORMAT_DATE_TIME4;
                                             } else {
-                                                $formatting = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX15;
+                                                $formatting = NumberFormat::FORMAT_DATE_XLSX15;
                                             }
                                             break;
                                         case 'time':
@@ -619,12 +626,12 @@ class Ods extends BaseReader implements IReader
 
                                             $timeValue = $cellData->getAttributeNS($officeNs, 'time-value');
 
-                                            $dataValue = \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(
+                                            $dataValue = Date::PHPToExcel(
                                                 strtotime(
                                                     '01-01-1970 ' . implode(':', sscanf($timeValue, 'PT%dH%dM%dS'))
                                                 )
                                             );
-                                            $formatting = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME4;
+                                            $formatting = NumberFormat::FORMAT_DATE_TIME4;
                                             break;
                                         default:
                                             $dataValue = null;
@@ -723,11 +730,11 @@ class Ods extends BaseReader implements IReader
                                         $columnTo = $columnID;
 
                                         if ($cellData->hasAttributeNS($tableNs, 'number-columns-spanned')) {
-                                            $columnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnID);
+                                            $columnIndex = Cell::columnIndexFromString($columnID);
                                             $columnIndex += (int) $cellData->getAttributeNS($tableNs, 'number-columns-spanned');
                                             $columnIndex -= 2;
 
-                                            $columnTo = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($columnIndex);
+                                            $columnTo = Cell::stringFromColumnIndex($columnIndex);
                                         }
 
                                         $rowTo = $rowID;
@@ -795,11 +802,11 @@ class Ods extends BaseReader implements IReader
     /**
      * @param string $is
      *
-     * @return \PhpOffice\PhpSpreadsheet\RichText
+     * @return RichText
      */
     private function parseRichText($is)
     {
-        $value = new \PhpOffice\PhpSpreadsheet\RichText();
+        $value = new RichText();
         $value->createText($is);
 
         return $value;
diff --git a/src/PhpSpreadsheet/Reader/Slk.php b/src/PhpSpreadsheet/Reader/Slk.php
index dbe2cd0f..5a0950a6 100644
--- a/src/PhpSpreadsheet/Reader/Slk.php
+++ b/src/PhpSpreadsheet/Reader/Slk.php
@@ -2,6 +2,12 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -151,7 +157,7 @@ class Slk extends BaseReader implements IReader
             $columnIndex = 0;
 
             // convert SYLK encoded $rowData to UTF-8
-            $rowData = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::SYLKtoUTF8($rowData);
+            $rowData = StringHelper::SYLKtoUTF8($rowData);
 
             // explode each row at semicolons while taking into account that literal semicolon (;)
             // is escaped like this (;;)
@@ -178,7 +184,7 @@ class Slk extends BaseReader implements IReader
             }
         }
 
-        $worksheetInfo[0]['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex']);
+        $worksheetInfo[0]['lastColumnLetter'] = Cell::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex']);
         $worksheetInfo[0]['totalColumns'] = $worksheetInfo[0]['lastColumnIndex'] + 1;
 
         // Close file
@@ -194,12 +200,12 @@ class Slk extends BaseReader implements IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename)
     {
         // Create new Spreadsheet
-        $spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+        $spreadsheet = new Spreadsheet();
 
         // Load into this instance
         return $this->loadIntoExisting($pFilename, $spreadsheet);
@@ -209,13 +215,13 @@ class Slk extends BaseReader implements IReader
      * Loads PhpSpreadsheet from file into PhpSpreadsheet instance.
      *
      * @param string $pFilename
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
-    public function loadIntoExisting($pFilename, \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function loadIntoExisting($pFilename, Spreadsheet $spreadsheet)
     {
         // Open file
         if (!$this->canRead($pFilename)) {
@@ -241,7 +247,7 @@ class Slk extends BaseReader implements IReader
         // loop through one row (line) at a time in the file
         while (($rowData = fgets($fileHandle)) !== false) {
             // convert SYLK encoded $rowData to UTF-8
-            $rowData = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::SYLKtoUTF8($rowData);
+            $rowData = StringHelper::SYLKtoUTF8($rowData);
 
             // explode each row at semicolons while taking into account that literal semicolon (;)
             // is escaped like this (;;)
@@ -274,16 +280,16 @@ class Slk extends BaseReader implements IReader
                                         $formatArray['font']['bold'] = true;
                                         break;
                                     case 'T':
-                                        $formatArray['borders']['top']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $formatArray['borders']['top']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'B':
-                                        $formatArray['borders']['bottom']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $formatArray['borders']['bottom']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'L':
-                                        $formatArray['borders']['left']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $formatArray['borders']['left']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'R':
-                                        $formatArray['borders']['right']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $formatArray['borders']['right']['style'] = Border::BORDER_THIN;
                                         break;
                                 }
                             }
@@ -342,7 +348,7 @@ class Slk extends BaseReader implements IReader
                                         if ($columnReference[0] == '[') {
                                             $columnReference = $column + trim($columnReference, '[]');
                                         }
-                                        $A1CellReference = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($columnReference - 1) . $rowReference;
+                                        $A1CellReference = Cell::stringFromColumnIndex($columnReference - 1) . $rowReference;
 
                                         $value = substr_replace($value, $A1CellReference, $cellReference[0][1], strlen($cellReference[0][0]));
                                     }
@@ -355,13 +361,13 @@ class Slk extends BaseReader implements IReader
                             break;
                     }
                 }
-                $columnLetter = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column - 1);
-                $cellData = \PhpOffice\PhpSpreadsheet\Calculation::unwrapResult($cellData);
+                $columnLetter = Cell::stringFromColumnIndex($column - 1);
+                $cellData = Calculation::unwrapResult($cellData);
 
                 // Set cell value
                 $spreadsheet->getActiveSheet()->getCell($columnLetter . $row)->setValue(($hasCalculatedValue) ? $cellDataFormula : $cellData);
                 if ($hasCalculatedValue) {
-                    $cellData = \PhpOffice\PhpSpreadsheet\Calculation::unwrapResult($cellData);
+                    $cellData = Calculation::unwrapResult($cellData);
                     $spreadsheet->getActiveSheet()->getCell($columnLetter . $row)->setCalculatedValue($cellData);
                 }
             //    Read cell formatting
@@ -395,16 +401,16 @@ class Slk extends BaseReader implements IReader
                                         $styleData['font']['bold'] = true;
                                         break;
                                     case 'T':
-                                        $styleData['borders']['top']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $styleData['borders']['top']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'B':
-                                        $styleData['borders']['bottom']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $styleData['borders']['bottom']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'L':
-                                        $styleData['borders']['left']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $styleData['borders']['left']['style'] = Border::BORDER_THIN;
                                         break;
                                     case 'R':
-                                        $styleData['borders']['right']['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN;
+                                        $styleData['borders']['right']['style'] = Border::BORDER_THIN;
                                         break;
                                 }
                             }
@@ -412,22 +418,22 @@ class Slk extends BaseReader implements IReader
                     }
                 }
                 if (($formatStyle > '') && ($column > '') && ($row > '')) {
-                    $columnLetter = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column - 1);
+                    $columnLetter = Cell::stringFromColumnIndex($column - 1);
                     if (isset($this->formats[$formatStyle])) {
                         $spreadsheet->getActiveSheet()->getStyle($columnLetter . $row)->applyFromArray($this->formats[$formatStyle]);
                     }
                 }
                 if ((!empty($styleData)) && ($column > '') && ($row > '')) {
-                    $columnLetter = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column - 1);
+                    $columnLetter = Cell::stringFromColumnIndex($column - 1);
                     $spreadsheet->getActiveSheet()->getStyle($columnLetter . $row)->applyFromArray($styleData);
                 }
                 if ($columnWidth > '') {
                     if ($startCol == $endCol) {
-                        $startCol = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($startCol - 1);
+                        $startCol = Cell::stringFromColumnIndex($startCol - 1);
                         $spreadsheet->getActiveSheet()->getColumnDimension($startCol)->setWidth($columnWidth);
                     } else {
-                        $startCol = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($startCol - 1);
-                        $endCol = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($endCol - 1);
+                        $startCol = Cell::stringFromColumnIndex($startCol - 1);
+                        $endCol = Cell::stringFromColumnIndex($endCol - 1);
                         $spreadsheet->getActiveSheet()->getColumnDimension($startCol)->setWidth($columnWidth);
                         do {
                             $spreadsheet->getActiveSheet()->getColumnDimension(++$startCol)->setWidth($columnWidth);
diff --git a/src/PhpSpreadsheet/Reader/Xls.php b/src/PhpSpreadsheet/Reader/Xls.php
index 801b27d7..a7fe48e4 100644
--- a/src/PhpSpreadsheet/Reader/Xls.php
+++ b/src/PhpSpreadsheet/Reader/Xls.php
@@ -2,7 +2,31 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\NamedRange;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\CodePage;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\Escher;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE;
 use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Shared\OLE;
+use PhpOffice\PhpSpreadsheet\Shared\OLERead;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Borders;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Worksheet\SheetView;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -194,7 +218,7 @@ class Xls extends BaseReader implements IReader
     /**
      * Workbook to be returned by the reader.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheet;
 
@@ -426,13 +450,13 @@ class Xls extends BaseReader implements IReader
 
         try {
             // Use ParseXL for the hard work.
-            $ole = new \PhpOffice\PhpSpreadsheet\Shared\OLERead();
+            $ole = new OLERead();
 
             // get excel data
             $ole->read($pFilename);
 
             return true;
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+        } catch (PhpSpreadsheetException $e) {
             return false;
         }
     }
@@ -586,7 +610,7 @@ class Xls extends BaseReader implements IReader
                 }
             }
 
-            $tmpInfo['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
+            $tmpInfo['lastColumnLetter'] = Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
             $tmpInfo['totalColumns'] = $tmpInfo['lastColumnIndex'] + 1;
 
             $worksheetInfo[] = $tmpInfo;
@@ -602,7 +626,7 @@ class Xls extends BaseReader implements IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename)
     {
@@ -610,7 +634,7 @@ class Xls extends BaseReader implements IReader
         $this->loadOLE($pFilename);
 
         // Initialisations
-        $this->spreadsheet = new \PhpOffice\PhpSpreadsheet\Spreadsheet();
+        $this->spreadsheet = new Spreadsheet();
         $this->spreadsheet->removeSheetByIndex(0); // remove 1st sheet
         if (!$this->readDataOnly) {
             $this->spreadsheet->removeCellStyleXfByIndex(0); // remove the default style
@@ -762,7 +786,7 @@ class Xls extends BaseReader implements IReader
 
         // treat MSODRAWINGGROUP records, workbook-level Escher
         if (!$this->readDataOnly && $this->drawingGroupData) {
-            $escherWorkbook = new \PhpOffice\PhpSpreadsheet\Shared\Escher();
+            $escherWorkbook = new Escher();
             $reader = new Xls\Escher($escherWorkbook);
             $escherWorkbook = $reader->load($this->drawingGroupData);
         }
@@ -980,7 +1004,7 @@ class Xls extends BaseReader implements IReader
 
             // treat MSODRAWING records, sheet-level Escher
             if (!$this->readDataOnly && $this->drawingData) {
-                $escherWorksheet = new \PhpOffice\PhpSpreadsheet\Shared\Escher();
+                $escherWorksheet = new Escher();
                 $reader = new Xls\Escher($escherWorksheet);
                 $escherWorksheet = $reader->load($this->drawingData);
 
@@ -1000,8 +1024,8 @@ class Xls extends BaseReader implements IReader
                     }
 
                     // calculate the width and height of the shape
-                    list($startColumn, $startRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($spContainer->getStartCoordinates());
-                    list($endColumn, $endRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($spContainer->getEndCoordinates());
+                    list($startColumn, $startRow) = Cell::coordinateFromString($spContainer->getStartCoordinates());
+                    list($endColumn, $endRow) = Cell::coordinateFromString($spContainer->getEndCoordinates());
 
                     $startOffsetX = $spContainer->getStartOffsetX();
                     $startOffsetY = $spContainer->getStartOffsetY();
@@ -1047,7 +1071,7 @@ class Xls extends BaseReader implements IReader
                             // need check because some blip types are not supported by Escher reader such as EMF
                             if ($blip = $BSE->getBlip()) {
                                 $ih = imagecreatefromstring($blip->getData());
-                                $drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing();
+                                $drawing = new MemoryDrawing();
                                 $drawing->setImageResource($ih);
 
                                 // width, height, offsetX, offsetY
@@ -1058,13 +1082,13 @@ class Xls extends BaseReader implements IReader
                                 $drawing->setOffsetY($offsetY);
 
                                 switch ($blipType) {
-                                    case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_JPEG:
-                                        $drawing->setRenderingFunction(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_JPEG);
-                                        $drawing->setMimeType(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::MIMETYPE_JPEG);
+                                    case BSE::BLIPTYPE_JPEG:
+                                        $drawing->setRenderingFunction(MemoryDrawing::RENDERING_JPEG);
+                                        $drawing->setMimeType(MemoryDrawing::MIMETYPE_JPEG);
                                         break;
-                                    case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG:
-                                        $drawing->setRenderingFunction(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_PNG);
-                                        $drawing->setMimeType(\PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::MIMETYPE_PNG);
+                                    case BSE::BLIPTYPE_PNG:
+                                        $drawing->setRenderingFunction(MemoryDrawing::RENDERING_PNG);
+                                        $drawing->setMimeType(MemoryDrawing::MIMETYPE_PNG);
                                         break;
                                 }
 
@@ -1082,10 +1106,10 @@ class Xls extends BaseReader implements IReader
             // treat SHAREDFMLA records
             if ($this->version == self::XLS_BIFF8) {
                 foreach ($this->sharedFormulaParts as $cell => $baseCell) {
-                    list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($cell);
+                    list($column, $row) = Cell::coordinateFromString($cell);
                     if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($column, $row, $this->phpSheet->getTitle())) {
                         $formula = $this->getFormulaFromStructure($this->sharedFormulas[$baseCell], $cell);
-                        $this->phpSheet->getCell($cell)->setValueExplicit('=' . $formula, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA);
+                        $this->phpSheet->getCell($cell)->setValueExplicit('=' . $formula, Cell\DataType::TYPE_FORMULA);
                     }
                 }
             }
@@ -1157,8 +1181,8 @@ class Xls extends BaseReader implements IReader
 
                                     $coordinateStrings = explode(':', $extractedRange);
                                     if (count($coordinateStrings) == 2) {
-                                        list($firstColumn, $firstRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($coordinateStrings[0]);
-                                        list($lastColumn, $lastRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($coordinateStrings[1]);
+                                        list($firstColumn, $firstRow) = Cell::coordinateFromString($coordinateStrings[0]);
+                                        list($lastColumn, $lastRow) = Cell::coordinateFromString($coordinateStrings[1]);
 
                                         if ($firstColumn == 'A' and $lastColumn == 'IV') {
                                             // then we have repeating rows
@@ -1187,7 +1211,7 @@ class Xls extends BaseReader implements IReader
 
                         $scope = ($definedName['scope'] == 0) ? null : $this->spreadsheet->getSheetByName($this->sheets[$definedName['scope'] - 1]['name']);
 
-                        $this->spreadsheet->addNamedRange(new \PhpOffice\PhpSpreadsheet\NamedRange((string) $definedName['name'], $docSheet, $extractedRange, $localOnly, $scope));
+                        $this->spreadsheet->addNamedRange(new NamedRange((string) $definedName['name'], $docSheet, $extractedRange, $localOnly, $scope));
                     }
                 }
                     //    Named Value
@@ -1263,7 +1287,7 @@ class Xls extends BaseReader implements IReader
     private function loadOLE($pFilename)
     {
         // OLE reader
-        $ole = new \PhpOffice\PhpSpreadsheet\Shared\OLERead();
+        $ole = new OLERead();
         // get excel data,
         $ole->read($pFilename);
         // Get workbook data: workbook stream + sheet streams
@@ -1334,12 +1358,12 @@ class Xls extends BaseReader implements IReader
                 case 0x1E: // null-terminated string prepended by dword string length
                     $byteLength = self::getInt4d($this->summaryInformation, $secOffset + 4 + $offset);
                     $value = substr($this->summaryInformation, $secOffset + 8 + $offset, $byteLength);
-                    $value = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($value, 'UTF-8', $codePage);
+                    $value = StringHelper::convertEncoding($value, 'UTF-8', $codePage);
                     $value = rtrim($value);
                     break;
                 case 0x40: // Filetime (64-bit value representing the number of 100-nanosecond intervals since January 1, 1601)
                     // PHP-time
-                    $value = \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE2LocalDate(substr($this->summaryInformation, $secOffset + 4 + $offset, 8));
+                    $value = OLE::OLE2LocalDate(substr($this->summaryInformation, $secOffset + 4 + $offset, 8));
                     break;
                 case 0x47: // Clipboard format
                     // not needed yet, fix later if necessary
@@ -1348,7 +1372,7 @@ class Xls extends BaseReader implements IReader
 
             switch ($id) {
                 case 0x01:    //    Code Page
-                    $codePage = \PhpOffice\PhpSpreadsheet\Shared\CodePage::numberToName($value);
+                    $codePage = CodePage::numberToName($value);
                     break;
                 case 0x02:    //    Title
                     $this->spreadsheet->getProperties()->setTitle($value);
@@ -1472,12 +1496,12 @@ class Xls extends BaseReader implements IReader
                 case 0x1E:    //    null-terminated string prepended by dword string length
                     $byteLength = self::getInt4d($this->documentSummaryInformation, $secOffset + 4 + $offset);
                     $value = substr($this->documentSummaryInformation, $secOffset + 8 + $offset, $byteLength);
-                    $value = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($value, 'UTF-8', $codePage);
+                    $value = StringHelper::convertEncoding($value, 'UTF-8', $codePage);
                     $value = rtrim($value);
                     break;
                 case 0x40:    //    Filetime (64-bit value representing the number of 100-nanosecond intervals since January 1, 1601)
                     // PHP-Time
-                    $value = \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE2LocalDate(substr($this->documentSummaryInformation, $secOffset + 4 + $offset, 8));
+                    $value = OLE::OLE2LocalDate(substr($this->documentSummaryInformation, $secOffset + 4 + $offset, 8));
                     break;
                 case 0x47:    //    Clipboard format
                     // not needed yet, fix later if necessary
@@ -1486,7 +1510,7 @@ class Xls extends BaseReader implements IReader
 
             switch ($id) {
                 case 0x01:    //    Code Page
-                    $codePage = \PhpOffice\PhpSpreadsheet\Shared\CodePage::numberToName($value);
+                    $codePage = CodePage::numberToName($value);
                     break;
                 case 0x02:    //    Category
                     $this->spreadsheet->getProperties()->setCategory($value);
@@ -1636,7 +1660,7 @@ class Xls extends BaseReader implements IReader
         // it is possible to use a compressed format,
         // which omits the high bytes of all characters, if they are all zero
         if (($is16Bit & 0x01) === 0) {
-            $textStr = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::ConvertEncoding($textStr, 'UTF-8', 'ISO-8859-1');
+            $textStr = StringHelper::ConvertEncoding($textStr, 'UTF-8', 'ISO-8859-1');
         } else {
             $textStr = $this->decodeCodepage($textStr);
         }
@@ -1861,7 +1885,7 @@ class Xls extends BaseReader implements IReader
         // offset: 0; size: 2; code page identifier
         $codepage = self::getInt2d($recordData, 0);
 
-        $this->codepage = \PhpOffice\PhpSpreadsheet\Shared\CodePage::numberToName($codepage);
+        $this->codepage = CodePage::numberToName($codepage);
     }
 
     /**
@@ -1885,9 +1909,9 @@ class Xls extends BaseReader implements IReader
         $this->pos += 4 + $length;
 
         // offset: 0; size: 2; 0 = base 1900, 1 = base 1904
-        \PhpOffice\PhpSpreadsheet\Shared\Date::setExcelCalendar(\PhpOffice\PhpSpreadsheet\Shared\Date::CALENDAR_WINDOWS_1900);
+        Date::setExcelCalendar(Date::CALENDAR_WINDOWS_1900);
         if (ord($recordData[0]) == 1) {
-            \PhpOffice\PhpSpreadsheet\Shared\Date::setExcelCalendar(\PhpOffice\PhpSpreadsheet\Shared\Date::CALENDAR_MAC_1904);
+            Date::setExcelCalendar(Date::CALENDAR_MAC_1904);
         }
     }
 
@@ -1903,7 +1927,7 @@ class Xls extends BaseReader implements IReader
         $this->pos += 4 + $length;
 
         if (!$this->readDataOnly) {
-            $objFont = new \PhpOffice\PhpSpreadsheet\Style\Font();
+            $objFont = new Font();
 
             // offset: 0; size: 2; height of the font (in twips = 1/20 of a point)
             $size = self::getInt2d($recordData, 0);
@@ -1953,16 +1977,16 @@ class Xls extends BaseReader implements IReader
                 case 0x00:
                     break; // no underline
                 case 0x01:
-                    $objFont->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE);
+                    $objFont->setUnderline(Font::UNDERLINE_SINGLE);
                     break;
                 case 0x02:
-                    $objFont->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLE);
+                    $objFont->setUnderline(Font::UNDERLINE_DOUBLE);
                     break;
                 case 0x21:
-                    $objFont->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLEACCOUNTING);
+                    $objFont->setUnderline(Font::UNDERLINE_SINGLEACCOUNTING);
                     break;
                 case 0x22:
-                    $objFont->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLEACCOUNTING);
+                    $objFont->setUnderline(Font::UNDERLINE_DOUBLEACCOUNTING);
                     break;
             }
 
@@ -2040,7 +2064,7 @@ class Xls extends BaseReader implements IReader
         // move stream pointer to next record
         $this->pos += 4 + $length;
 
-        $objStyle = new \PhpOffice\PhpSpreadsheet\Style();
+        $objStyle = new Style();
 
         if (!$this->readDataOnly) {
             // offset:  0; size: 2; Index to FONT record
@@ -2058,7 +2082,7 @@ class Xls extends BaseReader implements IReader
             if (isset($this->formats[$numberFormatIndex])) {
                 // then we have user-defined format code
                 $numberformat = ['code' => $this->formats[$numberFormatIndex]];
-            } elseif (($code = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::builtInFormatCode($numberFormatIndex)) !== '') {
+            } elseif (($code = NumberFormat::builtInFormatCode($numberFormatIndex)) !== '') {
                 // then we have built-in format code
                 $numberformat = ['code' => $code];
             } else {
@@ -2072,11 +2096,11 @@ class Xls extends BaseReader implements IReader
             $xfTypeProt = self::getInt2d($recordData, 4);
             // bit 0; mask 0x01; 1 = cell is locked
             $isLocked = (0x01 & $xfTypeProt) >> 0;
-            $objStyle->getProtection()->setLocked($isLocked ? \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT : \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED);
+            $objStyle->getProtection()->setLocked($isLocked ? Protection::PROTECTION_INHERIT : Protection::PROTECTION_UNPROTECTED);
 
             // bit 1; mask 0x02; 1 = Formula is hidden
             $isHidden = (0x02 & $xfTypeProt) >> 1;
-            $objStyle->getProtection()->setHidden($isHidden ? \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED : \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED);
+            $objStyle->getProtection()->setHidden($isHidden ? Protection::PROTECTION_PROTECTED : Protection::PROTECTION_UNPROTECTED);
 
             // bit 2; mask 0x04; 0 = Cell XF, 1 = Cell Style XF
             $isCellStyleXf = (0x04 & $xfTypeProt) >> 2;
@@ -2086,25 +2110,25 @@ class Xls extends BaseReader implements IReader
             $horAlign = (0x07 & ord($recordData[6])) >> 0;
             switch ($horAlign) {
                 case 0:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_GENERAL);
                     break;
                 case 1:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_LEFT);
                     break;
                 case 2:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER);
                     break;
                 case 3:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_RIGHT);
                     break;
                 case 4:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_FILL);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_FILL);
                     break;
                 case 5:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_JUSTIFY);
                     break;
                 case 6:
-                    $objStyle->getAlignment()->setHorizontal(\PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS);
+                    $objStyle->getAlignment()->setHorizontal(Alignment::HORIZONTAL_CENTER_CONTINUOUS);
                     break;
             }
             // bit 3, mask 0x08; wrap text
@@ -2121,16 +2145,16 @@ class Xls extends BaseReader implements IReader
             $vertAlign = (0x70 & ord($recordData[6])) >> 4;
             switch ($vertAlign) {
                 case 0:
-                    $objStyle->getAlignment()->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP);
+                    $objStyle->getAlignment()->setVertical(Alignment::VERTICAL_TOP);
                     break;
                 case 1:
-                    $objStyle->getAlignment()->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER);
+                    $objStyle->getAlignment()->setVertical(Alignment::VERTICAL_CENTER);
                     break;
                 case 2:
-                    $objStyle->getAlignment()->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM);
+                    $objStyle->getAlignment()->setVertical(Alignment::VERTICAL_BOTTOM);
                     break;
                 case 3:
-                    $objStyle->getAlignment()->setVertical(\PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY);
+                    $objStyle->getAlignment()->setVertical(Alignment::VERTICAL_JUSTIFY);
                     break;
             }
 
@@ -2195,13 +2219,13 @@ class Xls extends BaseReader implements IReader
                 $diagonalUp = (0x80000000 & self::getInt4d($recordData, 10)) >> 31 ? true : false;
 
                 if ($diagonalUp == false && $diagonalDown == false) {
-                    $objStyle->getBorders()->setDiagonalDirection(\PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_NONE);
+                    $objStyle->getBorders()->setDiagonalDirection(Borders::DIAGONAL_NONE);
                 } elseif ($diagonalUp == true && $diagonalDown == false) {
-                    $objStyle->getBorders()->setDiagonalDirection(\PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_UP);
+                    $objStyle->getBorders()->setDiagonalDirection(Borders::DIAGONAL_UP);
                 } elseif ($diagonalUp == false && $diagonalDown == true) {
-                    $objStyle->getBorders()->setDiagonalDirection(\PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_DOWN);
+                    $objStyle->getBorders()->setDiagonalDirection(Borders::DIAGONAL_DOWN);
                 } elseif ($diagonalUp == true && $diagonalDown == true) {
-                    $objStyle->getBorders()->setDiagonalDirection(\PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_BOTH);
+                    $objStyle->getBorders()->setDiagonalDirection(Borders::DIAGONAL_BOTH);
                 }
 
                 // offset: 14; size: 4;
@@ -2562,16 +2586,16 @@ class Xls extends BaseReader implements IReader
         // offset: 4; size: 1; sheet state
         switch (ord($recordData[4])) {
             case 0x00:
-                $sheetState = \PhpOffice\PhpSpreadsheet\Worksheet::SHEETSTATE_VISIBLE;
+                $sheetState = Worksheet::SHEETSTATE_VISIBLE;
                 break;
             case 0x01:
-                $sheetState = \PhpOffice\PhpSpreadsheet\Worksheet::SHEETSTATE_HIDDEN;
+                $sheetState = Worksheet::SHEETSTATE_HIDDEN;
                 break;
             case 0x02:
-                $sheetState = \PhpOffice\PhpSpreadsheet\Worksheet::SHEETSTATE_VERYHIDDEN;
+                $sheetState = Worksheet::SHEETSTATE_VERYHIDDEN;
                 break;
             default:
-                $sheetState = \PhpOffice\PhpSpreadsheet\Worksheet::SHEETSTATE_VISIBLE;
+                $sheetState = Worksheet::SHEETSTATE_VISIBLE;
                 break;
         }
 
@@ -2768,7 +2792,7 @@ class Xls extends BaseReader implements IReader
 
             try {
                 $formula = $this->getFormulaFromStructure($formulaStructure);
-            } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+            } catch (PhpSpreadsheetException $e) {
                 $formula = '';
             }
 
@@ -3064,7 +3088,7 @@ class Xls extends BaseReader implements IReader
                 $cl = self::getInt2d($recordData, 2 + 6 * $i + 4);
 
                 // not sure why two column indexes are necessary?
-                $this->phpSheet->setBreakByColumnAndRow($cf, $r, \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_ROW);
+                $this->phpSheet->setBreakByColumnAndRow($cf, $r, Worksheet::BREAK_ROW);
             }
         }
     }
@@ -3091,7 +3115,7 @@ class Xls extends BaseReader implements IReader
                 $rl = self::getInt2d($recordData, 2 + 6 * $i + 4);
 
                 // not sure why two row indexes are necessary?
-                $this->phpSheet->setBreakByColumnAndRow($c, $rf, \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_COLUMN);
+                $this->phpSheet->setBreakByColumnAndRow($c, $rf, Worksheet::BREAK_COLUMN);
             }
         }
     }
@@ -3292,10 +3316,10 @@ class Xls extends BaseReader implements IReader
                 $this->phpSheet->getPageSetup()->setPaperSize($paperSize);
                 switch ($isPortrait) {
                     case 0:
-                        $this->phpSheet->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE);
+                        $this->phpSheet->getPageSetup()->setOrientation(PageSetup::ORIENTATION_LANDSCAPE);
                         break;
                     case 1:
-                        $this->phpSheet->getPageSetup()->setOrientation(\PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_PORTRAIT);
+                        $this->phpSheet->getPageSetup()->setOrientation(PageSetup::ORIENTATION_PORTRAIT);
                         break;
                 }
 
@@ -3562,7 +3586,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; index to column
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         // Read cell?
         if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -3580,7 +3604,7 @@ class Xls extends BaseReader implements IReader
             }
 
             // add cell
-            $cell->setValueExplicit($numValue, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC);
+            $cell->setValueExplicit($numValue, Cell\DataType::TYPE_NUMERIC);
         }
     }
 
@@ -3606,7 +3630,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; index to column
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         $emptyCell = true;
         // Read cell?
@@ -3620,18 +3644,18 @@ class Xls extends BaseReader implements IReader
             // add cell
             if (($fmtRuns = $this->sst[$index]['fmtRuns']) && !$this->readDataOnly) {
                 // then we should treat as rich text
-                $richText = new \PhpOffice\PhpSpreadsheet\RichText();
+                $richText = new RichText();
                 $charPos = 0;
                 $sstCount = count($this->sst[$index]['fmtRuns']);
                 for ($i = 0; $i <= $sstCount; ++$i) {
                     if (isset($fmtRuns[$i])) {
-                        $text = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::substring($this->sst[$index]['value'], $charPos, $fmtRuns[$i]['charPos'] - $charPos);
+                        $text = StringHelper::substring($this->sst[$index]['value'], $charPos, $fmtRuns[$i]['charPos'] - $charPos);
                         $charPos = $fmtRuns[$i]['charPos'];
                     } else {
-                        $text = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::substring($this->sst[$index]['value'], $charPos, \PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($this->sst[$index]['value']));
+                        $text = StringHelper::substring($this->sst[$index]['value'], $charPos, StringHelper::countCharacters($this->sst[$index]['value']));
                     }
 
-                    if (\PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($text) > 0) {
+                    if (StringHelper::countCharacters($text) > 0) {
                         if ($i == 0) { // first text run, no style
                             $richText->createText($text);
                         } else {
@@ -3651,13 +3675,13 @@ class Xls extends BaseReader implements IReader
                 }
                 if ($this->readEmptyCells || trim($richText->getPlainText()) !== '') {
                     $cell = $this->phpSheet->getCell($columnString . ($row + 1));
-                    $cell->setValueExplicit($richText, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING);
+                    $cell->setValueExplicit($richText, Cell\DataType::TYPE_STRING);
                     $emptyCell = false;
                 }
             } else {
                 if ($this->readEmptyCells || trim($this->sst[$index]['value']) !== '') {
                     $cell = $this->phpSheet->getCell($columnString . ($row + 1));
-                    $cell->setValueExplicit($this->sst[$index]['value'], \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING);
+                    $cell->setValueExplicit($this->sst[$index]['value'], Cell\DataType::TYPE_STRING);
                     $emptyCell = false;
                 }
             }
@@ -3699,7 +3723,7 @@ class Xls extends BaseReader implements IReader
         $offset = 4;
 
         for ($i = 0; $i < $columns; ++$i) {
-            $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($colFirst + $i);
+            $columnString = Cell::stringFromColumnIndex($colFirst + $i);
 
             // Read cell?
             if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -3715,7 +3739,7 @@ class Xls extends BaseReader implements IReader
                 }
 
                 // add cell value
-                $cell->setValueExplicit($numValue, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC);
+                $cell->setValueExplicit($numValue, Cell\DataType::TYPE_NUMERIC);
             }
 
             $offset += 6;
@@ -3743,7 +3767,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size 2; index to column
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         // Read cell?
         if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -3759,7 +3783,7 @@ class Xls extends BaseReader implements IReader
             }
 
             // add cell value
-            $cell->setValueExplicit($numValue, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC);
+            $cell->setValueExplicit($numValue, Cell\DataType::TYPE_NUMERIC);
         }
     }
 
@@ -3784,7 +3808,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; col index
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         // offset: 20: size: variable; formula structure
         $formulaStructure = substr($recordData, 20);
@@ -3808,7 +3832,7 @@ class Xls extends BaseReader implements IReader
             // get the base cell, grab tExp token
             $baseRow = self::getInt2d($formulaStructure, 3);
             $baseCol = self::getInt2d($formulaStructure, 5);
-            $this->_baseCell = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($baseCol) . ($baseRow + 1);
+            $this->_baseCell = Cell::stringFromColumnIndex($baseCol) . ($baseRow + 1);
         }
 
         // Read cell?
@@ -3826,7 +3850,7 @@ class Xls extends BaseReader implements IReader
             // offset: 6; size: 8; result of the formula
             if ((ord($recordData[6]) == 0) && (ord($recordData[12]) == 255) && (ord($recordData[13]) == 255)) {
                 // String formula. Result follows in appended STRING record
-                $dataType = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING;
+                $dataType = Cell\DataType::TYPE_STRING;
 
                 // read possible SHAREDFMLA record
                 $code = self::getInt2d($this->data, $this->pos);
@@ -3840,23 +3864,23 @@ class Xls extends BaseReader implements IReader
                 && (ord($recordData[12]) == 255)
                 && (ord($recordData[13]) == 255)) {
                 // Boolean formula. Result is in +2; 0=false, 1=true
-                $dataType = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_BOOL;
+                $dataType = Cell\DataType::TYPE_BOOL;
                 $value = (bool) ord($recordData[8]);
             } elseif ((ord($recordData[6]) == 2)
                 && (ord($recordData[12]) == 255)
                 && (ord($recordData[13]) == 255)) {
                 // Error formula. Error code is in +2
-                $dataType = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_ERROR;
+                $dataType = Cell\DataType::TYPE_ERROR;
                 $value = Xls\ErrorCode::lookup(ord($recordData[8]));
             } elseif ((ord($recordData[6]) == 3)
                 && (ord($recordData[12]) == 255)
                 && (ord($recordData[13]) == 255)) {
                 // Formula result is a null string
-                $dataType = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NULL;
+                $dataType = Cell\DataType::TYPE_NULL;
                 $value = '';
             } else {
                 // forumla result is a number, first 14 bytes like _NUMBER record
-                $dataType = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC;
+                $dataType = Cell\DataType::TYPE_NUMERIC;
                 $value = self::extractNumber(substr($recordData, 6, 8));
             }
 
@@ -3875,8 +3899,8 @@ class Xls extends BaseReader implements IReader
                         throw new Exception('Not BIFF8. Can only read BIFF8 formulas');
                     }
                     $formula = $this->getFormulaFromStructure($formulaStructure); // get formula in human language
-                    $cell->setValueExplicit('=' . $formula, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA);
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                    $cell->setValueExplicit('=' . $formula, Cell\DataType::TYPE_FORMULA);
+                } catch (PhpSpreadsheetException $e) {
                     $cell->setValueExplicit($value, $dataType);
                 }
             } else {
@@ -3968,7 +3992,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; column index
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         // Read cell?
         if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -3987,13 +4011,13 @@ class Xls extends BaseReader implements IReader
                     $value = (bool) $boolErr;
 
                     // add cell value
-                    $cell->setValueExplicit($value, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_BOOL);
+                    $cell->setValueExplicit($value, Cell\DataType::TYPE_BOOL);
                     break;
                 case 1: // error type
                     $value = Xls\ErrorCode::lookup($boolErr);
 
                     // add cell value
-                    $cell->setValueExplicit($value, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_ERROR);
+                    $cell->setValueExplicit($value, Cell\DataType::TYPE_ERROR);
                     break;
             }
 
@@ -4030,7 +4054,7 @@ class Xls extends BaseReader implements IReader
         // add style information
         if (!$this->readDataOnly && $this->readEmptyCells) {
             for ($i = 0; $i < $length / 2 - 3; ++$i) {
-                $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($fc + $i);
+                $columnString = Cell::stringFromColumnIndex($fc + $i);
 
                 // Read cell?
                 if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -4066,7 +4090,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; index to column
         $column = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column);
+        $columnString = Cell::stringFromColumnIndex($column);
 
         // Read cell?
         if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -4084,7 +4108,7 @@ class Xls extends BaseReader implements IReader
             }
             if ($this->readEmptyCells || trim($value) !== '') {
                 $cell = $this->phpSheet->getCell($columnString . ($row + 1));
-                $cell->setValueExplicit($value, \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING);
+                $cell->setValueExplicit($value, Cell\DataType::TYPE_STRING);
 
                 if (!$this->readDataOnly) {
                     // add cell style
@@ -4110,7 +4134,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; col index
         $col = self::getInt2d($recordData, 2);
-        $columnString = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col);
+        $columnString = Cell::stringFromColumnIndex($col);
 
         // Read cell?
         if (($this->getReadFilter() !== null) && $this->getReadFilter()->readCell($columnString, $row + 1, $this->phpSheet->getTitle())) {
@@ -4237,9 +4261,9 @@ class Xls extends BaseReader implements IReader
 
         //FIXME: set $firstVisibleRow and $firstVisibleColumn
 
-        if ($this->phpSheet->getSheetView()->getView() !== \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_LAYOUT) {
+        if ($this->phpSheet->getSheetView()->getView() !== SheetView::SHEETVIEW_PAGE_LAYOUT) {
             //NOTE: this setting is inferior to page layout view(Excel2007-)
-            $view = $isPageBreakPreview ? \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW : \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_NORMAL;
+            $view = $isPageBreakPreview ? SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW : SheetView::SHEETVIEW_NORMAL;
             $this->phpSheet->getSheetView()->setView($view);
             if ($this->version === self::XLS_BIFF8) {
                 $zoomScale = $isPageBreakPreview ? $zoomscaleInPageBreakPreview : $zoomscaleInNormalView;
@@ -4280,7 +4304,7 @@ class Xls extends BaseReader implements IReader
         $fWhitespaceHidden = ($grbit >> 3) & 0x01; //no support
 
         if ($fPageLayoutView === 1) {
-            $this->phpSheet->getSheetView()->setView(\PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_LAYOUT);
+            $this->phpSheet->getSheetView()->setView(SheetView::SHEETVIEW_PAGE_LAYOUT);
             $this->phpSheet->getSheetView()->setZoomScale($wScalePLV); //set by Excel2007 only if SHEETVIEW_PAGE_LAYOUT
         }
         //otherwise, we cannot know whether SHEETVIEW_PAGE_LAYOUT or SHEETVIEW_PAGE_BREAK_PREVIEW.
@@ -4327,7 +4351,7 @@ class Xls extends BaseReader implements IReader
 
             if ($this->frozen) {
                 // frozen panes
-                $this->phpSheet->freezePane(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($px) . ($py + 1));
+                $this->phpSheet->freezePane(Cell::stringFromColumnIndex($px) . ($py + 1));
             }
                 // unfrozen panes; split windows; not supported by PhpSpreadsheet core
         }
@@ -4388,7 +4412,7 @@ class Xls extends BaseReader implements IReader
         $includeCellRange = true;
         if ($this->getReadFilter() !== null) {
             $includeCellRange = false;
-            $rangeBoundaries = \PhpOffice\PhpSpreadsheet\Cell::getRangeBoundaries($cellRangeAddress);
+            $rangeBoundaries = Cell::getRangeBoundaries($cellRangeAddress);
             ++$rangeBoundaries[1][0];
             for ($row = $rangeBoundaries[0][1]; $row <= $rangeBoundaries[1][1]; ++$row) {
                 for ($column = $rangeBoundaries[0][0]; $column != $rangeBoundaries[1][0]; ++$column) {
@@ -4446,7 +4470,7 @@ class Xls extends BaseReader implements IReader
             // offset: 0; size: 8; cell range address of all cells containing this hyperlink
             try {
                 $cellRange = $this->readBIFF8CellRangeAddressFixed($recordData);
-            } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+            } catch (PhpSpreadsheetException $e) {
                 return;
             }
 
@@ -4596,7 +4620,7 @@ class Xls extends BaseReader implements IReader
             }
 
             // apply the hyperlink to all the relevant cells
-            foreach (\PhpOffice\PhpSpreadsheet\Cell::extractAllCellReferencesInRange($cellRange) as $coordinate) {
+            foreach (Cell::extractAllCellReferencesInRange($cellRange) as $coordinate) {
                 $this->phpSheet->getCell($coordinate)->getHyperLink()->setUrl($url);
             }
         }
@@ -4636,28 +4660,28 @@ class Xls extends BaseReader implements IReader
         $type = (0x0000000F & $options) >> 0;
         switch ($type) {
             case 0x00:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_NONE;
+                $type = DataValidation::TYPE_NONE;
                 break;
             case 0x01:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_WHOLE;
+                $type = DataValidation::TYPE_WHOLE;
                 break;
             case 0x02:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_DECIMAL;
+                $type = DataValidation::TYPE_DECIMAL;
                 break;
             case 0x03:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST;
+                $type = DataValidation::TYPE_LIST;
                 break;
             case 0x04:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_DATE;
+                $type = DataValidation::TYPE_DATE;
                 break;
             case 0x05:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_TIME;
+                $type = DataValidation::TYPE_TIME;
                 break;
             case 0x06:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_TEXTLENGTH;
+                $type = DataValidation::TYPE_TEXTLENGTH;
                 break;
             case 0x07:
-                $type = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_CUSTOM;
+                $type = DataValidation::TYPE_CUSTOM;
                 break;
         }
 
@@ -4665,13 +4689,13 @@ class Xls extends BaseReader implements IReader
         $errorStyle = (0x00000070 & $options) >> 4;
         switch ($errorStyle) {
             case 0x00:
-                $errorStyle = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_STOP;
+                $errorStyle = DataValidation::STYLE_STOP;
                 break;
             case 0x01:
-                $errorStyle = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_WARNING;
+                $errorStyle = DataValidation::STYLE_WARNING;
                 break;
             case 0x02:
-                $errorStyle = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION;
+                $errorStyle = DataValidation::STYLE_INFORMATION;
                 break;
         }
 
@@ -4695,28 +4719,28 @@ class Xls extends BaseReader implements IReader
         $operator = (0x00F00000 & $options) >> 20;
         switch ($operator) {
             case 0x00:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_BETWEEN;
+                $operator = DataValidation::OPERATOR_BETWEEN;
                 break;
             case 0x01:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_NOTBETWEEN;
+                $operator = DataValidation::OPERATOR_NOTBETWEEN;
                 break;
             case 0x02:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_EQUAL;
+                $operator = DataValidation::OPERATOR_EQUAL;
                 break;
             case 0x03:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_NOTEQUAL;
+                $operator = DataValidation::OPERATOR_NOTEQUAL;
                 break;
             case 0x04:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_GREATERTHAN;
+                $operator = DataValidation::OPERATOR_GREATERTHAN;
                 break;
             case 0x05:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_LESSTHAN;
+                $operator = DataValidation::OPERATOR_LESSTHAN;
                 break;
             case 0x06:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_GREATERTHANOREQUAL;
+                $operator = DataValidation::OPERATOR_GREATERTHANOREQUAL;
                 break;
             case 0x07:
-                $operator = \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_LESSTHANOREQUAL;
+                $operator = DataValidation::OPERATOR_LESSTHANOREQUAL;
                 break;
         }
 
@@ -4755,10 +4779,10 @@ class Xls extends BaseReader implements IReader
             $formula1 = $this->getFormulaFromStructure($formula1);
 
             // in list type validity, null characters are used as item separators
-            if ($type == \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST) {
+            if ($type == DataValidation::TYPE_LIST) {
                 $formula1 = str_replace(chr(0), ',', $formula1);
             }
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+        } catch (PhpSpreadsheetException $e) {
             return;
         }
         $offset += $sz1;
@@ -4775,7 +4799,7 @@ class Xls extends BaseReader implements IReader
         $formula2 = pack('v', $sz2) . $formula2; // prepend the length
         try {
             $formula2 = $this->getFormulaFromStructure($formula2);
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+        } catch (PhpSpreadsheetException $e) {
             return;
         }
         $offset += $sz2;
@@ -4786,7 +4810,7 @@ class Xls extends BaseReader implements IReader
 
         foreach ($cellRangeAddresses as $cellRange) {
             $stRange = $this->phpSheet->shrinkRangeToFit($cellRange);
-            foreach (\PhpOffice\PhpSpreadsheet\Cell::extractAllCellReferencesInRange($stRange) as $coordinate) {
+            foreach (Cell::extractAllCellReferencesInRange($stRange) as $coordinate) {
                 $objValidation = $this->phpSheet->getCell($coordinate)->getDataValidation();
                 $objValidation->setType($type);
                 $objValidation->setErrorStyle($errorStyle);
@@ -4981,7 +5005,7 @@ class Xls extends BaseReader implements IReader
             for ($i = 0; $i < $cref; ++$i) {
                 try {
                     $cellRange = $this->readBIFF8CellRangeAddressFixed(substr($recordData, 27 + 8 * $i, 8));
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     return;
                 }
                 $cellRanges[] = $cellRange;
@@ -5063,7 +5087,7 @@ class Xls extends BaseReader implements IReader
                 }
                 //imagepng($ih, 'image.png');
 
-                $drawing = new \PhpOffice\PhpSpreadsheet\Worksheet\Drawing();
+                $drawing = new Drawing();
                 $drawing->setPath($filename);
                 $drawing->setWorksheet($this->phpSheet);
                 break;
@@ -6624,7 +6648,7 @@ class Xls extends BaseReader implements IReader
                     $cellAddress = $this->readBIFF8CellAddress(substr($formulaData, 3, 4));
 
                     $data = "$sheetRange!$cellAddress";
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     // deleted sheet reference
                     $data = '#REF!';
                 }
@@ -6642,7 +6666,7 @@ class Xls extends BaseReader implements IReader
                     $cellRangeAddress = $this->readBIFF8CellRangeAddress(substr($formulaData, 3, 8));
 
                     $data = "$sheetRange!$cellRangeAddress";
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     // deleted sheet reference
                     $data = '#REF!';
                 }
@@ -6676,7 +6700,7 @@ class Xls extends BaseReader implements IReader
 
         // offset: 2; size: 2; index to column or column offset + relative flags
         // bit: 7-0; mask 0x00FF; column index
-        $column = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex(0x00FF & self::getInt2d($cellAddressStructure, 2));
+        $column = Cell::stringFromColumnIndex(0x00FF & self::getInt2d($cellAddressStructure, 2));
 
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($cellAddressStructure, 2))) {
@@ -6702,8 +6726,8 @@ class Xls extends BaseReader implements IReader
      */
     private function readBIFF8CellAddressB($cellAddressStructure, $baseCell = 'A1')
     {
-        list($baseCol, $baseRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($baseCell);
-        $baseCol = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($baseCol) - 1;
+        list($baseCol, $baseRow) = Cell::coordinateFromString($baseCell);
+        $baseCol = Cell::columnIndexFromString($baseCol) - 1;
 
         // offset: 0; size: 2; index to row (0... 65535) (or offset (-32768... 32767))
         $rowIndex = self::getInt2d($cellAddressStructure, 0);
@@ -6715,11 +6739,11 @@ class Xls extends BaseReader implements IReader
 
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($cellAddressStructure, 2))) {
-            $column = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($colIndex);
+            $column = Cell::stringFromColumnIndex($colIndex);
             $column = '$' . $column;
         } else {
             $colIndex = ($colIndex <= 127) ? $colIndex : $colIndex - 256;
-            $column = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($baseCol + $colIndex);
+            $column = Cell::stringFromColumnIndex($baseCol + $colIndex);
         }
 
         // bit: 15; mask 0x8000; (1 = relative row index, 0 = absolute row index)
@@ -6764,8 +6788,8 @@ class Xls extends BaseReader implements IReader
         }
 
         // column index to letter
-        $fc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($fc);
-        $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($lc);
+        $fc = Cell::stringFromColumnIndex($fc);
+        $lc = Cell::stringFromColumnIndex($lc);
 
         if ($fr == $lr and $fc == $lc) {
             return "$fc$fr";
@@ -6805,8 +6829,8 @@ class Xls extends BaseReader implements IReader
         }
 
         // column index to letter
-        $fc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($fc);
-        $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($lc);
+        $fc = Cell::stringFromColumnIndex($fc);
+        $lc = Cell::stringFromColumnIndex($lc);
 
         if ($fr == $lr and $fc == $lc) {
             return "$fc$fr";
@@ -6838,7 +6862,7 @@ class Xls extends BaseReader implements IReader
         // offset: 4; size: 2; index to first column or column offset + relative flags
 
         // bit: 7-0; mask 0x00FF; column index
-        $fc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex(0x00FF & self::getInt2d($subData, 4));
+        $fc = Cell::stringFromColumnIndex(0x00FF & self::getInt2d($subData, 4));
 
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($subData, 4))) {
@@ -6853,7 +6877,7 @@ class Xls extends BaseReader implements IReader
         // offset: 6; size: 2; index to last column or column offset + relative flags
 
         // bit: 7-0; mask 0x00FF; column index
-        $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex(0x00FF & self::getInt2d($subData, 6));
+        $lc = Cell::stringFromColumnIndex(0x00FF & self::getInt2d($subData, 6));
 
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($subData, 6))) {
@@ -6880,8 +6904,8 @@ class Xls extends BaseReader implements IReader
      */
     private function readBIFF8CellRangeAddressB($subData, $baseCell = 'A1')
     {
-        list($baseCol, $baseRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($baseCell);
-        $baseCol = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($baseCol) - 1;
+        list($baseCol, $baseRow) = Cell::coordinateFromString($baseCell);
+        $baseCol = Cell::columnIndexFromString($baseCol) - 1;
 
         // TODO: if cell range is just a single cell, should this funciton
         // not just return e.g. 'A1' and not 'A1:A1' ?
@@ -6900,12 +6924,12 @@ class Xls extends BaseReader implements IReader
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($subData, 4))) {
             // absolute column index
-            $fc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($fcIndex);
+            $fc = Cell::stringFromColumnIndex($fcIndex);
             $fc = '$' . $fc;
         } else {
             // column offset
             $fcIndex = ($fcIndex <= 127) ? $fcIndex : $fcIndex - 256;
-            $fc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($baseCol + $fcIndex);
+            $fc = Cell::stringFromColumnIndex($baseCol + $fcIndex);
         }
 
         // bit: 15; mask 0x8000; (1 = relative row index, 0 = absolute row index)
@@ -6924,17 +6948,17 @@ class Xls extends BaseReader implements IReader
         // bit: 7-0; mask 0x00FF; column index
         $lcIndex = 0x00FF & self::getInt2d($subData, 6);
         $lcIndex = ($lcIndex <= 127) ? $lcIndex : $lcIndex - 256;
-        $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($baseCol + $lcIndex);
+        $lc = Cell::stringFromColumnIndex($baseCol + $lcIndex);
 
         // bit: 14; mask 0x4000; (1 = relative column index, 0 = absolute column index)
         if (!(0x4000 & self::getInt2d($subData, 6))) {
             // absolute column index
-            $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($lcIndex);
+            $lc = Cell::stringFromColumnIndex($lcIndex);
             $lc = '$' . $lc;
         } else {
             // column offset
             $lcIndex = ($lcIndex <= 127) ? $lcIndex : $lcIndex - 256;
-            $lc = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($baseCol + $lcIndex);
+            $lc = Cell::stringFromColumnIndex($baseCol + $lcIndex);
         }
 
         // bit: 15; mask 0x8000; (1 = relative row index, 0 = absolute row index)
@@ -7395,7 +7419,7 @@ class Xls extends BaseReader implements IReader
             $string = self::uncompressByteString($string);
         }
 
-        return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($string, 'UTF-8', 'UTF-16LE');
+        return StringHelper::convertEncoding($string, 'UTF-8', 'UTF-16LE');
     }
 
     /**
@@ -7425,7 +7449,7 @@ class Xls extends BaseReader implements IReader
      */
     private function decodeCodepage($string)
     {
-        return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($string, 'UTF-8', $this->codepage);
+        return StringHelper::convertEncoding($string, 'UTF-8', $this->codepage);
     }
 
     /**
@@ -7467,7 +7491,7 @@ class Xls extends BaseReader implements IReader
 
     private function parseRichText($is)
     {
-        $value = new \PhpOffice\PhpSpreadsheet\RichText();
+        $value = new RichText();
         $value->createText($is);
 
         return $value;
diff --git a/src/PhpSpreadsheet/Reader/Xls/Color.php b/src/PhpSpreadsheet/Reader/Xls/Color.php
index 32ea6148..6d3d6340 100644
--- a/src/PhpSpreadsheet/Reader/Xls/Color.php
+++ b/src/PhpSpreadsheet/Reader/Xls/Color.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader\Xls;
 
+use PhpOffice\PhpSpreadsheet\Reader\Xls;
+
 class Color
 {
     /**
@@ -24,7 +26,7 @@ class Color
         }
 
         // default color table
-        if ($version == \PhpOffice\PhpSpreadsheet\Reader\Xls::XLS_BIFF8) {
+        if ($version == Xls::XLS_BIFF8) {
             return Color\BIFF8::lookup($color);
         }
 
diff --git a/src/PhpSpreadsheet/Reader/Xls/Escher.php b/src/PhpSpreadsheet/Reader/Xls/Escher.php
index fd6ae1d1..270272c6 100644
--- a/src/PhpSpreadsheet/Reader/Xls/Escher.php
+++ b/src/PhpSpreadsheet/Reader/Xls/Escher.php
@@ -2,6 +2,16 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader\Xls;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Reader\Xls;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -100,7 +110,7 @@ class Escher
         // Parse Escher stream
         while ($this->pos < $this->dataSize) {
             // offset: 2; size: 2: Record Type
-            $fbt = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos + 2);
+            $fbt = Xls::getInt2d($this->data, $this->pos + 2);
 
             switch ($fbt) {
                 case self::DGGCONTAINER:
@@ -172,15 +182,15 @@ class Escher
     private function readDefault()
     {
         // offset 0; size: 2; recVer and recInstance
-        $verInstance = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos);
+        $verInstance = Xls::getInt2d($this->data, $this->pos);
 
         // offset: 2; size: 2: Record Type
-        $fbt = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos + 2);
+        $fbt = Xls::getInt2d($this->data, $this->pos + 2);
 
         // bit: 0-3; mask: 0x000F; recVer
         $recVer = (0x000F & $verInstance) >> 0;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -192,14 +202,14 @@ class Escher
      */
     private function readDggContainer()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // record is a container, read contents
-        $dggContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer();
+        $dggContainer = new DggContainer();
         $this->object->setDggContainer($dggContainer);
         $reader = new self($dggContainer);
         $reader->load($recordData);
@@ -210,7 +220,7 @@ class Escher
      */
     private function readDgg()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -222,14 +232,14 @@ class Escher
      */
     private function readBstoreContainer()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // record is a container, read contents
-        $bstoreContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer();
+        $bstoreContainer = new BstoreContainer();
         $this->object->setBstoreContainer($bstoreContainer);
         $reader = new self($bstoreContainer);
         $reader->load($recordData);
@@ -243,16 +253,16 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // add BSE to BstoreContainer
-        $BSE = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE();
+        $BSE = new BSE();
         $this->object->addBSE($BSE);
 
         $BSE->setBLIPType($recInstance);
@@ -267,16 +277,16 @@ class Escher
         $rgbUid = substr($recordData, 2, 16);
 
         // offset: 18; size: 2; tag
-        $tag = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 18);
+        $tag = Xls::getInt2d($recordData, 18);
 
         // offset: 20; size: 4; size of BLIP in bytes
-        $size = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($recordData, 20);
+        $size = Xls::getInt4d($recordData, 20);
 
         // offset: 24; size: 4; number of references to this BLIP
-        $cRef = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($recordData, 24);
+        $cRef = Xls::getInt4d($recordData, 24);
 
         // offset: 28; size: 4; MSOFO file offset
-        $foDelay = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($recordData, 28);
+        $foDelay = Xls::getInt4d($recordData, 28);
 
         // offset: 32; size: 1; unused1
         $unused1 = ord($recordData[32]);
@@ -297,7 +307,7 @@ class Escher
         $blipData = substr($recordData, 36 + $cbName);
 
         // record is a container, read contents
-        $reader = new \PhpOffice\PhpSpreadsheet\Reader\Xls\Escher($BSE);
+        $reader = new self($BSE);
         $reader->load($blipData);
     }
 
@@ -309,9 +319,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -336,7 +346,7 @@ class Escher
         // offset: var; size: var; the raw image data
         $data = substr($recordData, $pos);
 
-        $blip = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip();
+        $blip = new Blip();
         $blip->setData($data);
 
         $this->object->setBlip($blip);
@@ -350,9 +360,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -377,7 +387,7 @@ class Escher
         // offset: var; size: var; the raw image data
         $data = substr($recordData, $pos);
 
-        $blip = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip();
+        $blip = new Blip();
         $blip->setData($data);
 
         $this->object->setBlip($blip);
@@ -391,9 +401,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -410,9 +420,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -424,7 +434,7 @@ class Escher
      */
     private function readSplitMenuColors()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -436,16 +446,16 @@ class Escher
      */
     private function readDgContainer()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // record is a container, read contents
-        $dgContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer();
+        $dgContainer = new DgContainer();
         $this->object->setDgContainer($dgContainer);
-        $reader = new \PhpOffice\PhpSpreadsheet\Reader\Xls\Escher($dgContainer);
+        $reader = new self($dgContainer);
         $escher = $reader->load($recordData);
     }
 
@@ -454,7 +464,7 @@ class Escher
      */
     private function readDg()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -468,16 +478,16 @@ class Escher
     {
         // context is either context DgContainer or SpgrContainer
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // record is a container, read contents
-        $spgrContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer();
+        $spgrContainer = new SpgrContainer();
 
-        if ($this->object instanceof \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer) {
+        if ($this->object instanceof DgContainer) {
             // DgContainer
             $this->object->setSpgrContainer($spgrContainer);
         } else {
@@ -494,11 +504,11 @@ class Escher
      */
     private function readSpContainer()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // add spContainer to spgrContainer
-        $spContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer();
+        $spContainer = new SpContainer();
         $this->object->addChild($spContainer);
 
         // move stream pointer to next record
@@ -514,7 +524,7 @@ class Escher
      */
     private function readSpgr()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -529,9 +539,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -546,9 +556,9 @@ class Escher
         // offset: 0; size: 2; recVer and recInstance
 
         // bit: 4-15; mask: 0xFFF0; recInstance
-        $recInstance = (0xFFF0 & \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($this->data, $this->pos)) >> 4;
+        $recInstance = (0xFFF0 & Xls::getInt2d($this->data, $this->pos)) >> 4;
 
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -560,38 +570,38 @@ class Escher
      */
     private function readClientAnchor()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
         $this->pos += 8 + $length;
 
         // offset: 2; size: 2; upper-left corner column index (0-based)
-        $c1 = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 2);
+        $c1 = Xls::getInt2d($recordData, 2);
 
         // offset: 4; size: 2; upper-left corner horizontal offset in 1/1024 of column width
-        $startOffsetX = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 4);
+        $startOffsetX = Xls::getInt2d($recordData, 4);
 
         // offset: 6; size: 2; upper-left corner row index (0-based)
-        $r1 = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 6);
+        $r1 = Xls::getInt2d($recordData, 6);
 
         // offset: 8; size: 2; upper-left corner vertical offset in 1/256 of row height
-        $startOffsetY = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 8);
+        $startOffsetY = Xls::getInt2d($recordData, 8);
 
         // offset: 10; size: 2; bottom-right corner column index (0-based)
-        $c2 = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 10);
+        $c2 = Xls::getInt2d($recordData, 10);
 
         // offset: 12; size: 2; bottom-right corner horizontal offset in 1/1024 of column width
-        $endOffsetX = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 12);
+        $endOffsetX = Xls::getInt2d($recordData, 12);
 
         // offset: 14; size: 2; bottom-right corner row index (0-based)
-        $r2 = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 14);
+        $r2 = Xls::getInt2d($recordData, 14);
 
         // offset: 16; size: 2; bottom-right corner vertical offset in 1/256 of row height
-        $endOffsetY = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($recordData, 16);
+        $endOffsetY = Xls::getInt2d($recordData, 16);
 
         // set the start coordinates
-        $this->object->setStartCoordinates(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c1) . ($r1 + 1));
+        $this->object->setStartCoordinates(Cell::stringFromColumnIndex($c1) . ($r1 + 1));
 
         // set the start offsetX
         $this->object->setStartOffsetX($startOffsetX);
@@ -600,7 +610,7 @@ class Escher
         $this->object->setStartOffsetY($startOffsetY);
 
         // set the end coordinates
-        $this->object->setEndCoordinates(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($c2) . ($r2 + 1));
+        $this->object->setEndCoordinates(Cell::stringFromColumnIndex($c2) . ($r2 + 1));
 
         // set the end offsetX
         $this->object->setEndOffsetX($endOffsetX);
@@ -614,7 +624,7 @@ class Escher
      */
     private function readClientData()
     {
-        $length = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($this->data, $this->pos + 4);
+        $length = Xls::getInt4d($this->data, $this->pos + 4);
         $recordData = substr($this->data, $this->pos + 8, $length);
 
         // move stream pointer to next record
@@ -637,7 +647,7 @@ class Escher
             $fopte = substr($data, 6 * $i, 6);
 
             // offset: 0; size: 2; opid
-            $opid = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt2d($fopte, 0);
+            $opid = Xls::getInt2d($fopte, 0);
 
             // bit: 0-13; mask: 0x3FFF; opid.opid
             $opidOpid = (0x3FFF & $opid) >> 0;
@@ -649,7 +659,7 @@ class Escher
             $opidFComplex = (0x8000 & $opid) >> 15;
 
             // offset: 2; size: 4; the value for this property
-            $op = \PhpOffice\PhpSpreadsheet\Reader\Xls::getInt4d($fopte, 2);
+            $op = Xls::getInt4d($fopte, 2);
 
             if ($opidFComplex) {
                 $complexData = substr($splicedComplexData, 0, $op);
diff --git a/src/PhpSpreadsheet/Reader/Xlsx.php b/src/PhpSpreadsheet/Reader/Xlsx.php
index a0e98187..3d39016d 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx.php
@@ -19,6 +19,7 @@ use PhpOffice\PhpSpreadsheet\Style;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use XMLReader;
 use ZipArchive;
 
 /**
@@ -219,7 +220,7 @@ class Xlsx extends BaseReader implements IReader
 
                         $fileWorksheet = $worksheets[(string) self::getArrayItem($eleSheet->attributes('http://schemas.openxmlformats.org/officeDocument/2006/relationships'), 'id')];
 
-                        $xml = new \XMLReader();
+                        $xml = new XMLReader();
                         $res = $xml->xml(
                             $this->securityScanFile(
                                 'zip://' . File::realpath($pFilename) . '#' . "$dir/$fileWorksheet"
@@ -231,12 +232,12 @@ class Xlsx extends BaseReader implements IReader
 
                         $currCells = 0;
                         while ($xml->read()) {
-                            if ($xml->name == 'row' && $xml->nodeType == \XMLReader::ELEMENT) {
+                            if ($xml->name == 'row' && $xml->nodeType == XMLReader::ELEMENT) {
                                 $row = $xml->getAttribute('r');
                                 $tmpInfo['totalRows'] = $row;
                                 $tmpInfo['totalColumns'] = max($tmpInfo['totalColumns'], $currCells);
                                 $currCells = 0;
-                            } elseif ($xml->name == 'c' && $xml->nodeType == \XMLReader::ELEMENT) {
+                            } elseif ($xml->name == 'c' && $xml->nodeType == XMLReader::ELEMENT) {
                                 ++$currCells;
                             }
                         }
diff --git a/src/PhpSpreadsheet/Reader/Xlsx/Chart.php b/src/PhpSpreadsheet/Reader/Xlsx/Chart.php
index 48564d6d..2e6c1d84 100644
--- a/src/PhpSpreadsheet/Reader/Xlsx/Chart.php
+++ b/src/PhpSpreadsheet/Reader/Xlsx/Chart.php
@@ -3,6 +3,16 @@
 namespace PhpOffice\PhpSpreadsheet\Reader\Xlsx;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\Layout;
+use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use SimpleXMLElement;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -29,11 +39,11 @@ use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 class Chart
 {
     /**
-     * @param \SimpleXMLElement $component
+     * @param SimpleXMLElement $component
      * @param string $name
      * @param string $format
      */
-    private static function getAttribute(\SimpleXMLElement $component, $name, $format)
+    private static function getAttribute(SimpleXMLElement $component, $name, $format)
     {
         $attributes = $component->attributes();
         if (isset($attributes[$name])) {
@@ -56,15 +66,15 @@ class Chart
         if (isset($color['rgb'])) {
             return (string) $color['rgb'];
         } elseif (isset($color['indexed'])) {
-            return \PhpOffice\PhpSpreadsheet\Style\Color::indexedColor($color['indexed'] - 7, $background)->getARGB();
+            return Color::indexedColor($color['indexed'] - 7, $background)->getARGB();
         }
     }
 
     /**
-     * @param \SimpleXMLElement $chartElements
+     * @param SimpleXMLElement $chartElements
      * @param string $chartName
      */
-    public static function readChart(\SimpleXMLElement $chartElements, $chartName)
+    public static function readChart(SimpleXMLElement $chartElements, $chartName)
     {
         $namespacesChartMeta = $chartElements->getNamespaces(true);
         $chartElementsC = $chartElements->children($namespacesChartMeta['c']);
@@ -164,9 +174,9 @@ class Chart
                                     }
                                 }
                                 if ($plotAreaLayout == null) {
-                                    $plotAreaLayout = new \PhpOffice\PhpSpreadsheet\Chart\Layout();
+                                    $plotAreaLayout = new Layout();
                                 }
-                                $plotArea = new \PhpOffice\PhpSpreadsheet\Chart\PlotArea($plotAreaLayout, $plotSeries);
+                                $plotArea = new PlotArea($plotAreaLayout, $plotSeries);
                                 self::setChartAttributes($plotAreaLayout, $plotAttributes);
                                 break;
                             case 'plotVisOnly':
@@ -195,7 +205,7 @@ class Chart
                                             break;
                                     }
                                 }
-                                $legend = new \PhpOffice\PhpSpreadsheet\Chart\Legend($legendPos, $legendLayout, $legendOverlay);
+                                $legend = new Legend($legendPos, $legendLayout, $legendOverlay);
                                 break;
                         }
                     }
@@ -206,7 +216,7 @@ class Chart
         return $chart;
     }
 
-    private static function chartTitle(\SimpleXMLElement $titleDetails, array $namespacesChartMeta)
+    private static function chartTitle(SimpleXMLElement $titleDetails, array $namespacesChartMeta)
     {
         $caption = [];
         $titleLayout = null;
@@ -228,7 +238,7 @@ class Chart
             }
         }
 
-        return new \PhpOffice\PhpSpreadsheet\Chart\Title($caption, $titleLayout);
+        return new Title($caption, $titleLayout);
     }
 
     private static function chartLayoutDetails($chartDetail, $namespacesChartMeta)
@@ -245,7 +255,7 @@ class Chart
             $layout[$detailKey] = self::getAttribute($detail, 'val', 'string');
         }
 
-        return new \PhpOffice\PhpSpreadsheet\Chart\Layout($layout);
+        return new Layout($layout);
     }
 
     private static function chartDataSeries($chartDetail, $namespacesChartMeta, $plotType)
@@ -297,7 +307,7 @@ class Chart
             }
         }
 
-        return new \PhpOffice\PhpSpreadsheet\Chart\DataSeries($plotType, $multiSeriesType, $plotOrder, $seriesLabel, $seriesCategory, $seriesValues, $smoothLine);
+        return new DataSeries($plotType, $multiSeriesType, $plotOrder, $seriesLabel, $seriesCategory, $seriesValues, $smoothLine);
     }
 
     private static function chartDataSeriesValueSet($seriesDetail, $namespacesChartMeta, $marker = null, $smoothLine = false)
@@ -306,24 +316,24 @@ class Chart
             $seriesSource = (string) $seriesDetail->strRef->f;
             $seriesData = self::chartDataSeriesValues($seriesDetail->strRef->strCache->children($namespacesChartMeta['c']), 's');
 
-            return new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
+            return new DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
         } elseif (isset($seriesDetail->numRef)) {
             $seriesSource = (string) $seriesDetail->numRef->f;
             $seriesData = self::chartDataSeriesValues($seriesDetail->numRef->numCache->children($namespacesChartMeta['c']));
 
-            return new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('Number', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
+            return new DataSeriesValues('Number', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
         } elseif (isset($seriesDetail->multiLvlStrRef)) {
             $seriesSource = (string) $seriesDetail->multiLvlStrRef->f;
             $seriesData = self::chartDataSeriesValuesMultiLevel($seriesDetail->multiLvlStrRef->multiLvlStrCache->children($namespacesChartMeta['c']), 's');
             $seriesData['pointCount'] = count($seriesData['dataValues']);
 
-            return new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
+            return new DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
         } elseif (isset($seriesDetail->multiLvlNumRef)) {
             $seriesSource = (string) $seriesDetail->multiLvlNumRef->f;
             $seriesData = self::chartDataSeriesValuesMultiLevel($seriesDetail->multiLvlNumRef->multiLvlNumCache->children($namespacesChartMeta['c']), 's');
             $seriesData['pointCount'] = count($seriesData['dataValues']);
 
-            return new \PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
+            return new DataSeriesValues('String', $seriesSource, $seriesData['formatCode'], $seriesData['pointCount'], $seriesData['dataValues'], $marker, $smoothLine);
         }
 
         return null;
@@ -399,9 +409,9 @@ class Chart
         ];
     }
 
-    private static function parseRichText(\SimpleXMLElement $titleDetailPart)
+    private static function parseRichText(SimpleXMLElement $titleDetailPart)
     {
-        $value = new \PhpOffice\PhpSpreadsheet\RichText();
+        $value = new RichText();
 
         foreach ($titleDetailPart as $titleDetailElementKey => $titleDetailElement) {
             if (isset($titleDetailElement->t)) {
@@ -419,7 +429,7 @@ class Chart
 
                 $fontColor = (self::getAttribute($titleDetailElement->rPr, 'color', 'string'));
                 if (!is_null($fontColor)) {
-                    $objText->getFont()->setColor(new \PhpOffice\PhpSpreadsheet\Style\Color(self::readColor($fontColor)));
+                    $objText->getFont()->setColor(new Color(self::readColor($fontColor)));
                 }
 
                 $bold = self::getAttribute($titleDetailElement->rPr, 'b', 'boolean');
@@ -444,11 +454,11 @@ class Chart
                 $underscore = (self::getAttribute($titleDetailElement->rPr, 'u', 'string'));
                 if (!is_null($underscore)) {
                     if ($underscore == 'sng') {
-                        $objText->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE);
+                        $objText->getFont()->setUnderline(Font::UNDERLINE_SINGLE);
                     } elseif ($underscore == 'dbl') {
-                        $objText->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLE);
+                        $objText->getFont()->setUnderline(Font::UNDERLINE_DOUBLE);
                     } else {
-                        $objText->getFont()->setUnderline(\PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_NONE);
+                        $objText->getFont()->setUnderline(Font::UNDERLINE_NONE);
                     }
                 }
 
@@ -497,10 +507,10 @@ class Chart
     }
 
     /**
-     * @param \PhpOffice\PhpSpreadsheet\Chart\Layout $plotArea
+     * @param Layout $plotArea
      * @param mixed $plotAttributes
      */
-    private static function setChartAttributes(\PhpOffice\PhpSpreadsheet\Chart\Layout $plotArea, $plotAttributes)
+    private static function setChartAttributes(Layout $plotArea, $plotAttributes)
     {
         foreach ($plotAttributes as $plotAttributeKey => $plotAttributeValue) {
             switch ($plotAttributeKey) {
diff --git a/src/PhpSpreadsheet/Reader/Xml.php b/src/PhpSpreadsheet/Reader/Xml.php
index 00e29808..d7aff065 100644
--- a/src/PhpSpreadsheet/Reader/Xml.php
+++ b/src/PhpSpreadsheet/Reader/Xml.php
@@ -2,8 +2,18 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use DateTimeZone;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Document\Properties;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Settings;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Font;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -126,7 +136,7 @@ class Xml extends BaseReader implements IReader
         $xml = simplexml_load_string(
             $this->securityScan(file_get_contents($pFilename)),
             'SimpleXMLElement',
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $namespaces = $xml->getNamespaces(true);
 
@@ -155,7 +165,7 @@ class Xml extends BaseReader implements IReader
         $xml = simplexml_load_string(
             $this->securityScan(file_get_contents($pFilename)),
             'SimpleXMLElement',
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $namespaces = $xml->getNamespaces(true);
 
@@ -201,7 +211,7 @@ class Xml extends BaseReader implements IReader
                 }
             }
 
-            $tmpInfo['lastColumnLetter'] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
+            $tmpInfo['lastColumnLetter'] = Cell::stringFromColumnIndex($tmpInfo['lastColumnIndex']);
             $tmpInfo['totalColumns'] = $tmpInfo['lastColumnIndex'] + 1;
 
             $worksheetInfo[] = $tmpInfo;
@@ -218,7 +228,7 @@ class Xml extends BaseReader implements IReader
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     public function load($pFilename)
     {
@@ -288,41 +298,41 @@ class Xml extends BaseReader implements IReader
      * Loads from file into Spreadsheet instance.
      *
      * @param string $pFilename
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
-    public function loadIntoExisting($pFilename, \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function loadIntoExisting($pFilename, Spreadsheet $spreadsheet)
     {
         $fromFormats = ['\-', '\ '];
         $toFormats = ['-', ' '];
 
         $underlineStyles = [
-            \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_NONE,
-            \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLE,
-            \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_DOUBLEACCOUNTING,
-            \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLE,
-            \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_SINGLEACCOUNTING,
+            Font::UNDERLINE_NONE,
+            Font::UNDERLINE_DOUBLE,
+            Font::UNDERLINE_DOUBLEACCOUNTING,
+            Font::UNDERLINE_SINGLE,
+            Font::UNDERLINE_SINGLEACCOUNTING,
         ];
         $verticalAlignmentStyles = [
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY,
+            Alignment::VERTICAL_BOTTOM,
+            Alignment::VERTICAL_TOP,
+            Alignment::VERTICAL_CENTER,
+            Alignment::VERTICAL_JUSTIFY,
         ];
         $horizontalAlignmentStyles = [
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS,
-            \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY,
+            Alignment::HORIZONTAL_GENERAL,
+            Alignment::HORIZONTAL_LEFT,
+            Alignment::HORIZONTAL_RIGHT,
+            Alignment::HORIZONTAL_CENTER,
+            Alignment::HORIZONTAL_CENTER_CONTINUOUS,
+            Alignment::HORIZONTAL_JUSTIFY,
         ];
 
-        $timezoneObj = new \DateTimeZone('Europe/London');
-        $GMT = new \DateTimeZone('UTC');
+        $timezoneObj = new DateTimeZone('Europe/London');
+        $GMT = new DateTimeZone('UTC');
 
         File::assertFile($pFilename);
         if (!$this->canRead($pFilename)) {
@@ -332,7 +342,7 @@ class Xml extends BaseReader implements IReader
         $xml = simplexml_load_string(
             $this->securityScan(file_get_contents($pFilename)),
             'SimpleXMLElement',
-            \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions()
+            Settings::getLibXmlLoaderOptions()
         );
         $namespaces = $xml->getNamespaces(true);
 
@@ -382,26 +392,26 @@ class Xml extends BaseReader implements IReader
             foreach ($xml->CustomDocumentProperties[0] as $propertyName => $propertyValue) {
                 $propertyAttributes = $propertyValue->attributes($namespaces['dt']);
                 $propertyName = preg_replace_callback('/_x([0-9a-z]{4})_/', ['self', 'hex2str'], $propertyName);
-                $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_UNKNOWN;
+                $propertyType = Properties::PROPERTY_TYPE_UNKNOWN;
                 switch ((string) $propertyAttributes) {
                     case 'string':
-                        $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_STRING;
+                        $propertyType = Properties::PROPERTY_TYPE_STRING;
                         $propertyValue = trim($propertyValue);
                         break;
                     case 'boolean':
-                        $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_BOOLEAN;
+                        $propertyType = Properties::PROPERTY_TYPE_BOOLEAN;
                         $propertyValue = (bool) $propertyValue;
                         break;
                     case 'integer':
-                        $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_INTEGER;
+                        $propertyType = Properties::PROPERTY_TYPE_INTEGER;
                         $propertyValue = (int) $propertyValue;
                         break;
                     case 'float':
-                        $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_FLOAT;
+                        $propertyType = Properties::PROPERTY_TYPE_FLOAT;
                         $propertyValue = (float) $propertyValue;
                         break;
                     case 'dateTime.tz':
-                        $propertyType = \PhpOffice\PhpSpreadsheet\Document\Properties::PROPERTY_TYPE_DATE;
+                        $propertyType = Properties::PROPERTY_TYPE_DATE;
                         $propertyValue = strtotime(trim($propertyValue));
                         break;
                 }
@@ -443,7 +453,7 @@ class Xml extends BaseReader implements IReader
                             foreach ($borderAttributes as $borderStyleKey => $borderStyleValue) {
                                 switch ($borderStyleKey) {
                                     case 'LineStyle':
-                                        $thisBorder['style'] = \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM;
+                                        $thisBorder['style'] = Border::BORDER_MEDIUM;
                                         break;
                                     case 'Weight':
                                         break;
@@ -550,7 +560,7 @@ class Xml extends BaseReader implements IReader
                 foreach ($worksheet->Table->Column as $columnData) {
                     $columnData_ss = $columnData->attributes($namespaces['ss']);
                     if (isset($columnData_ss['Index'])) {
-                        $columnID = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($columnData_ss['Index'] - 1);
+                        $columnID = Cell::stringFromColumnIndex($columnData_ss['Index'] - 1);
                     }
                     if (isset($columnData_ss['Width'])) {
                         $columnWidth = $columnData_ss['Width'];
@@ -574,7 +584,7 @@ class Xml extends BaseReader implements IReader
                     foreach ($rowData->Cell as $cell) {
                         $cell_ss = $cell->attributes($namespaces['ss']);
                         if (isset($cell_ss['Index'])) {
-                            $columnID = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($cell_ss['Index'] - 1);
+                            $columnID = Cell::stringFromColumnIndex($cell_ss['Index'] - 1);
                         }
                         $cellRange = $columnID . $rowID;
 
@@ -589,7 +599,7 @@ class Xml extends BaseReader implements IReader
                             $columnTo = $columnID;
                             if (isset($cell_ss['MergeAcross'])) {
                                 $additionalMergedCells += (int) $cell_ss['MergeAcross'];
-                                $columnTo = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex(\PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnID) + $cell_ss['MergeAcross'] - 1);
+                                $columnTo = Cell::stringFromColumnIndex(Cell::columnIndexFromString($columnID) + $cell_ss['MergeAcross'] - 1);
                             }
                             $rowTo = $rowID;
                             if (isset($cell_ss['MergeDown'])) {
@@ -611,7 +621,7 @@ class Xml extends BaseReader implements IReader
                         }
                         if (isset($cell->Data)) {
                             $cellValue = $cellData = $cell->Data;
-                            $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NULL;
+                            $type = Cell\DataType::TYPE_NULL;
                             $cellData_ss = $cellData->attributes($namespaces['ss']);
                             if (isset($cellData_ss['Type'])) {
                                 $cellDataType = $cellData_ss['Type'];
@@ -627,32 +637,32 @@ class Xml extends BaseReader implements IReader
                                     */
                                     case 'String':
                                         $cellValue = self::convertStringEncoding($cellValue, $this->charSet);
-                                        $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING;
+                                        $type = Cell\DataType::TYPE_STRING;
                                         break;
                                     case 'Number':
-                                        $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC;
+                                        $type = Cell\DataType::TYPE_NUMERIC;
                                         $cellValue = (float) $cellValue;
                                         if (floor($cellValue) == $cellValue) {
                                             $cellValue = (int) $cellValue;
                                         }
                                         break;
                                     case 'Boolean':
-                                        $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_BOOL;
+                                        $type = Cell\DataType::TYPE_BOOL;
                                         $cellValue = ($cellValue != 0);
                                         break;
                                     case 'DateTime':
-                                        $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC;
-                                        $cellValue = \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(strtotime($cellValue));
+                                        $type = Cell\DataType::TYPE_NUMERIC;
+                                        $cellValue = Date::PHPToExcel(strtotime($cellValue));
                                         break;
                                     case 'Error':
-                                        $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_ERROR;
+                                        $type = Cell\DataType::TYPE_ERROR;
                                         break;
                                 }
                             }
 
                             if ($hasCalculatedValue) {
-                                $type = \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA;
-                                $columnNumber = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnID);
+                                $type = Cell\DataType::TYPE_FORMULA;
+                                $columnNumber = Cell::columnIndexFromString($columnID);
                                 if (substr($cellDataFormula, 0, 3) == 'of:') {
                                     $cellDataFormula = substr($cellDataFormula, 3);
                                     $temp = explode('"', $cellDataFormula);
@@ -696,7 +706,7 @@ class Xml extends BaseReader implements IReader
                                                 if ($columnReference[0] == '[') {
                                                     $columnReference = $columnNumber + trim($columnReference, '[]');
                                                 }
-                                                $A1CellReference = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($columnReference - 1) . $rowReference;
+                                                $A1CellReference = Cell::stringFromColumnIndex($columnReference - 1) . $rowReference;
                                                 $value = substr_replace($value, $A1CellReference, $cellReference[0][1], strlen($cellReference[0][0]));
                                             }
                                         }
@@ -764,7 +774,7 @@ class Xml extends BaseReader implements IReader
     protected static function convertStringEncoding($string, $charset)
     {
         if ($charset != 'UTF-8') {
-            return \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($string, 'UTF-8', $charset);
+            return StringHelper::convertEncoding($string, 'UTF-8', $charset);
         }
 
         return $string;
@@ -772,7 +782,7 @@ class Xml extends BaseReader implements IReader
 
     protected function parseRichText($is)
     {
-        $value = new \PhpOffice\PhpSpreadsheet\RichText();
+        $value = new RichText();
 
         $value->createText(self::convertStringEncoding($is, $this->charSet));
 
diff --git a/src/PhpSpreadsheet/ReferenceHelper.php b/src/PhpSpreadsheet/ReferenceHelper.php
index 30eb9436..5bd291f2 100644
--- a/src/PhpSpreadsheet/ReferenceHelper.php
+++ b/src/PhpSpreadsheet/ReferenceHelper.php
@@ -807,7 +807,7 @@ class ReferenceHelper
     /**
      * Update named formulas (i.e. containing worksheet references / named ranges).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet Object to update
+     * @param Spreadsheet $spreadsheet Object to update
      * @param string $oldName Old name (name to replace)
      * @param string $newName New name
      */
diff --git a/src/PhpSpreadsheet/RichText/Run.php b/src/PhpSpreadsheet/RichText/Run.php
index 90fc21a9..a4d74173 100644
--- a/src/PhpSpreadsheet/RichText/Run.php
+++ b/src/PhpSpreadsheet/RichText/Run.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\RichText;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+
 /**
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,7 +30,7 @@ class Run extends TextElement implements ITextElement
     /**
      * Font.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Style\Font
+     * @var Font
      */
     private $font;
 
@@ -40,13 +43,13 @@ class Run extends TextElement implements ITextElement
     {
         // Initialise variables
         $this->setText($pText);
-        $this->font = new \PhpOffice\PhpSpreadsheet\Style\Font();
+        $this->font = new Font();
     }
 
     /**
      * Get font.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Font
+     * @return Font
      */
     public function getFont()
     {
@@ -56,13 +59,13 @@ class Run extends TextElement implements ITextElement
     /**
      * Set font.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Font $pFont Font
+     * @param Font $pFont Font
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return ITextElement
      */
-    public function setFont(\PhpOffice\PhpSpreadsheet\Style\Font $pFont = null)
+    public function setFont(Font $pFont = null)
     {
         $this->font = $pFont;
 
diff --git a/src/PhpSpreadsheet/Shared/CodePage.php b/src/PhpSpreadsheet/Shared/CodePage.php
index 6e56d231..a6ece3a6 100644
--- a/src/PhpSpreadsheet/Shared/CodePage.php
+++ b/src/PhpSpreadsheet/Shared/CodePage.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -32,7 +34,7 @@ class CodePage
      *
      * @param int $codePage Microsoft Code Page Indentifier
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return string Code Page Name
      */
@@ -44,7 +46,7 @@ class CodePage
             case 437:
                 return 'CP437'; //    OEM US
             case 720:
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Code page 720 not supported.'); //    OEM Arabic
+                throw new PhpSpreadsheetException('Code page 720 not supported.'); //    OEM Arabic
             case 737:
                 return 'CP737'; //    OEM Greek
             case 775:
@@ -146,12 +148,12 @@ class CodePage
             case 32768:
                 return 'MAC'; //    Apple Roman
             case 32769:
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Code page 32769 not supported.'); //    ANSI Latin I (BIFF2-BIFF3)
+                throw new PhpSpreadsheetException('Code page 32769 not supported.'); //    ANSI Latin I (BIFF2-BIFF3)
             case 65000:
                 return 'UTF-7'; //    Unicode (UTF-7)
             case 65001:
                 return 'UTF-8'; //    Unicode (UTF-8)
         }
-        throw new \PhpOffice\PhpSpreadsheet\Exception('Unknown codepage: ' . $codePage);
+        throw new PhpSpreadsheetException('Unknown codepage: ' . $codePage);
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/Date.php b/src/PhpSpreadsheet/Shared/Date.php
index a7409e38..185e643a 100644
--- a/src/PhpSpreadsheet/Shared/Date.php
+++ b/src/PhpSpreadsheet/Shared/Date.php
@@ -2,6 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use DateTimeInterface;
+use DateTimeZone;
+use PhpOffice\PhpSpreadsheet\Calculation\DateTime;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -112,7 +119,7 @@ class Date
     /**
      * Set the Default timezone to use for dates.
      *
-     * @param string|\DateTimeZone $timeZone The timezone to set for all Excel datetimestamp to PHP DateTime Object conversions
+     * @param string|DateTimeZone $timeZone The timezone to set for all Excel datetimestamp to PHP DateTime Object conversions
      *
      * @throws \Exception
      *
@@ -133,12 +140,12 @@ class Date
     /**
      * Return the Default timezone being used for dates.
      *
-     * @return \DateTimeZone The timezone being used as default for Excel timestamp to PHP DateTime object
+     * @return DateTimeZone The timezone being used as default for Excel timestamp to PHP DateTime object
      */
     public static function getDefaultTimezone()
     {
         if (self::$defaultTimeZone === null) {
-            self::$defaultTimeZone = new \DateTimeZone('UTC');
+            self::$defaultTimeZone = new DateTimeZone('UTC');
         }
 
         return self::$defaultTimeZone;
@@ -147,19 +154,19 @@ class Date
     /**
      * Validate a timezone.
      *
-     * @param string|\DateTimeZone $timeZone The timezone to validate, either as a timezone string or object
+     * @param string|DateTimeZone $timeZone The timezone to validate, either as a timezone string or object
      *
      * @throws \Exception
      *
-     * @return \DateTimeZone The timezone as a timezone object
-     * @return \DateTimeZone The timezone as a timezone object
+     * @return DateTimeZone The timezone as a timezone object
+     * @return DateTimeZone The timezone as a timezone object
      */
     protected static function validateTimeZone($timeZone)
     {
-        if (is_object($timeZone) && $timeZone instanceof \DateTimeZone) {
+        if (is_object($timeZone) && $timeZone instanceof DateTimeZone) {
             return $timeZone;
         } elseif (is_string($timeZone)) {
-            return new \DateTimeZone($timeZone);
+            return new DateTimeZone($timeZone);
         }
         throw new \Exception('Invalid timezone');
     }
@@ -168,7 +175,7 @@ class Date
      * Convert a MS serialized datetime value from Excel to a PHP Date/Time object.
      *
      * @param int|float $excelTimestamp MS Excel serialized date/time value
-     * @param \DateTimeZone|string|null $timeZone The timezone to assume for the Excel timestamp,
+     * @param DateTimeZone|string|null $timeZone The timezone to assume for the Excel timestamp,
      *                                                                        if you don't want to treat it as a UTC value
      *                                                                    Use the default (UST) unless you absolutely need a conversion
      *
@@ -209,7 +216,7 @@ class Date
      * Convert a MS serialized datetime value from Excel to a unix timestamp.
      *
      * @param int|float $excelTimestamp MS Excel serialized date/time value
-     * @param \DateTimeZone|string|null $timeZone The timezone to assume for the Excel timestamp,
+     * @param DateTimeZone|string|null $timeZone The timezone to assume for the Excel timestamp,
      *                                                                        if you don't want to treat it as a UTC value
      *                                                                    Use the default (UST) unless you absolutely need a conversion
      *
@@ -233,7 +240,7 @@ class Date
      */
     public static function PHPToExcel($dateValue)
     {
-        if ((is_object($dateValue)) && ($dateValue instanceof \DateTimeInterface)) {
+        if ((is_object($dateValue)) && ($dateValue instanceof DateTimeInterface)) {
             return self::dateTimeToExcel($dateValue);
         } elseif (is_numeric($dateValue)) {
             return self::timestampToExcel($dateValue);
@@ -247,11 +254,11 @@ class Date
     /**
      * Convert a PHP DateTime object to an MS Excel serialized date/time value.
      *
-     * @param \DateTimeInterface $dateValue PHP DateTime object
+     * @param DateTimeInterface $dateValue PHP DateTime object
      *
      * @return float MS Excel serialized date/time value
      */
-    public static function dateTimeToExcel(\DateTimeInterface $dateValue)
+    public static function dateTimeToExcel(DateTimeInterface $dateValue)
     {
         return self::formattedPHPToExcel(
             $dateValue->format('Y'),
@@ -266,7 +273,7 @@ class Date
     /**
      * Convert a Unix timestamp to an MS Excel serialized date/time value.
      *
-     * @param \DateTimeInterface $dateValue Unix Timestamp
+     * @param DateTimeInterface $dateValue Unix Timestamp
      *
      * @return float MS Excel serialized date/time value
      */
@@ -329,11 +336,11 @@ class Date
     /**
      * Is a given cell a date/time?
      *
-     * @param \PhpOffice\PhpSpreadsheet\Cell $pCell
+     * @param Cell $pCell
      *
      * @return bool
      */
-    public static function isDateTime(\PhpOffice\PhpSpreadsheet\Cell $pCell)
+    public static function isDateTime(Cell $pCell)
     {
         return self::isDateTimeFormat(
             $pCell->getWorksheet()->getStyle(
@@ -345,11 +352,11 @@ class Date
     /**
      * Is a given number format a date/time?
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\NumberFormat $pFormat
+     * @param NumberFormat $pFormat
      *
      * @return bool
      */
-    public static function isDateTimeFormat(\PhpOffice\PhpSpreadsheet\Style\NumberFormat $pFormat)
+    public static function isDateTimeFormat(NumberFormat $pFormat)
     {
         return self::isDateTimeFormatCode($pFormat->getFormatCode());
     }
@@ -365,7 +372,7 @@ class Date
      */
     public static function isDateTimeFormatCode($pFormatCode)
     {
-        if (strtolower($pFormatCode) === strtolower(\PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_GENERAL)) {
+        if (strtolower($pFormatCode) === strtolower(NumberFormat::FORMAT_GENERAL)) {
             //    "General" contains an epoch letter 'e', so we trap for it explicitly here (case-insensitive check)
             return false;
         }
@@ -377,28 +384,28 @@ class Date
         // Switch on formatcode
         switch ($pFormatCode) {
             //    Explicitly defined date formats
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDD2:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DDMMYYYY:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DMYSLASH:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DMYMINUS:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DMMINUS:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_MYMINUS:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_DATETIME:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME1:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME2:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME3:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME4:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME5:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME6:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME7:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_TIME8:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_YYYYMMDDSLASH:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX14:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX15:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX16:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX17:
-            case \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_DATE_XLSX22:
+            case NumberFormat::FORMAT_DATE_YYYYMMDD:
+            case NumberFormat::FORMAT_DATE_YYYYMMDD2:
+            case NumberFormat::FORMAT_DATE_DDMMYYYY:
+            case NumberFormat::FORMAT_DATE_DMYSLASH:
+            case NumberFormat::FORMAT_DATE_DMYMINUS:
+            case NumberFormat::FORMAT_DATE_DMMINUS:
+            case NumberFormat::FORMAT_DATE_MYMINUS:
+            case NumberFormat::FORMAT_DATE_DATETIME:
+            case NumberFormat::FORMAT_DATE_TIME1:
+            case NumberFormat::FORMAT_DATE_TIME2:
+            case NumberFormat::FORMAT_DATE_TIME3:
+            case NumberFormat::FORMAT_DATE_TIME4:
+            case NumberFormat::FORMAT_DATE_TIME5:
+            case NumberFormat::FORMAT_DATE_TIME6:
+            case NumberFormat::FORMAT_DATE_TIME7:
+            case NumberFormat::FORMAT_DATE_TIME8:
+            case NumberFormat::FORMAT_DATE_YYYYMMDDSLASH:
+            case NumberFormat::FORMAT_DATE_XLSX14:
+            case NumberFormat::FORMAT_DATE_XLSX15:
+            case NumberFormat::FORMAT_DATE_XLSX16:
+            case NumberFormat::FORMAT_DATE_XLSX17:
+            case NumberFormat::FORMAT_DATE_XLSX22:
                 return true;
         }
 
@@ -446,15 +453,15 @@ class Date
             return false;
         }
 
-        $dateValueNew = \PhpOffice\PhpSpreadsheet\Calculation\DateTime::DATEVALUE($dateValue);
+        $dateValueNew = DateTime::DATEVALUE($dateValue);
 
-        if ($dateValueNew === \PhpOffice\PhpSpreadsheet\Calculation\Functions::VALUE()) {
+        if ($dateValueNew === Functions::VALUE()) {
             return false;
         }
 
         if (strpos($dateValue, ':') !== false) {
-            $timeValue = \PhpOffice\PhpSpreadsheet\Calculation\DateTime::TIMEVALUE($dateValue);
-            if ($timeValue === \PhpOffice\PhpSpreadsheet\Calculation\Functions::VALUE()) {
+            $timeValue = DateTime::TIMEVALUE($dateValue);
+            if ($timeValue === Functions::VALUE()) {
                 return false;
             }
             $dateValueNew += $timeValue;
diff --git a/src/PhpSpreadsheet/Shared/Drawing.php b/src/PhpSpreadsheet/Shared/Drawing.php
index 436112be..0f88b8d7 100644
--- a/src/PhpSpreadsheet/Shared/Drawing.php
+++ b/src/PhpSpreadsheet/Shared/Drawing.php
@@ -70,13 +70,13 @@ class Drawing
         $name = $pDefaultFont->getName();
         $size = $pDefaultFont->getSize();
 
-        if (isset(\PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size])) {
+        if (isset(Font::$defaultColumnWidths[$name][$size])) {
             // Exact width can be determined
-            $colWidth = $pValue * \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size]['width'] / \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size]['px'];
+            $colWidth = $pValue * Font::$defaultColumnWidths[$name][$size]['width'] / Font::$defaultColumnWidths[$name][$size]['px'];
         } else {
             // We don't have data for this particular font and size, use approximation by
             // extrapolating from Calibri 11
-            $colWidth = $pValue * 11 * \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths['Calibri'][11]['width'] / \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths['Calibri'][11]['px'] / $size;
+            $colWidth = $pValue * 11 * Font::$defaultColumnWidths['Calibri'][11]['width'] / Font::$defaultColumnWidths['Calibri'][11]['px'] / $size;
         }
 
         return $colWidth;
@@ -96,13 +96,13 @@ class Drawing
         $name = $pDefaultFont->getName();
         $size = $pDefaultFont->getSize();
 
-        if (isset(\PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size])) {
+        if (isset(Font::$defaultColumnWidths[$name][$size])) {
             // Exact width can be determined
-            $colWidth = $pValue * \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size]['px'] / \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths[$name][$size]['width'];
+            $colWidth = $pValue * Font::$defaultColumnWidths[$name][$size]['px'] / Font::$defaultColumnWidths[$name][$size]['width'];
         } else {
             // We don't have data for this particular font and size, use approximation by
             // extrapolating from Calibri 11
-            $colWidth = $pValue * $size * \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths['Calibri'][11]['px'] / \PhpOffice\PhpSpreadsheet\Shared\Font::$defaultColumnWidths['Calibri'][11]['width'] / 11;
+            $colWidth = $pValue * $size * Font::$defaultColumnWidths['Calibri'][11]['px'] / Font::$defaultColumnWidths['Calibri'][11]['width'] / 11;
         }
 
         // Round pixels to closest integer
diff --git a/src/PhpSpreadsheet/Shared/Escher/DgContainer/SpgrContainer/SpContainer.php b/src/PhpSpreadsheet/Shared/Escher/DgContainer/SpgrContainer/SpContainer.php
index c2b6787a..cf5cef72 100644
--- a/src/PhpSpreadsheet/Shared/Escher/DgContainer/SpgrContainer/SpContainer.php
+++ b/src/PhpSpreadsheet/Shared/Escher/DgContainer/SpgrContainer/SpContainer.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer;
 
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,7 +31,7 @@ class SpContainer
     /**
      * Parent Shape Group Container.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer
+     * @var SpgrContainer
      */
     private $parent;
 
@@ -113,7 +115,7 @@ class SpContainer
     /**
      * Set parent Shape Group Container.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer $parent
+     * @param SpgrContainer $parent
      */
     public function setParent($parent)
     {
@@ -123,7 +125,7 @@ class SpContainer
     /**
      * Get the parent Shape Group Container.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer
+     * @return SpgrContainer
      */
     public function getParent()
     {
@@ -379,7 +381,7 @@ class SpContainer
         $nestingLevel = 0;
 
         $parent = $this->getParent();
-        while ($parent instanceof \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer) {
+        while ($parent instanceof SpgrContainer) {
             ++$nestingLevel;
             $parent = $parent->getParent();
         }
diff --git a/src/PhpSpreadsheet/Shared/File.php b/src/PhpSpreadsheet/Shared/File.php
index 9efd83ff..3b7b64ba 100644
--- a/src/PhpSpreadsheet/Shared/File.php
+++ b/src/PhpSpreadsheet/Shared/File.php
@@ -2,6 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use InvalidArgumentException;
 use ZipArchive;
 
 /**
@@ -151,16 +152,16 @@ class File
      *
      * @param string $filename
      *
-     * @throws \InvalidArgumentException
+     * @throws InvalidArgumentException
      */
     public static function assertFile($filename)
     {
         if (!is_file($filename)) {
-            throw new \InvalidArgumentException('File "' . $filename . '" does not exist.');
+            throw new InvalidArgumentException('File "' . $filename . '" does not exist.');
         }
 
         if (!is_readable($filename)) {
-            throw new \InvalidArgumentException('Could not open "' . $filename . '" for reading.');
+            throw new InvalidArgumentException('Could not open "' . $filename . '" for reading.');
         }
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/Font.php b/src/PhpSpreadsheet/Shared/Font.php
index befc2751..33ce9ace 100644
--- a/src/PhpSpreadsheet/Shared/Font.php
+++ b/src/PhpSpreadsheet/Shared/Font.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\RichText;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -236,7 +239,7 @@ class Font
      * Calculate an (approximate) OpenXML column width, based on font size and text contained.
      *
      * @param \PhpOffice\PhpSpreadsheet\Style\Font $font Font object
-     * @param \PhpOffice\PhpSpreadsheet\RichText|string $cellText Text to calculate width
+     * @param RichText|string $cellText Text to calculate width
      * @param int $rotation Rotation angle
      * @param \PhpOffice\PhpSpreadsheet\Style\Font|null $defaultFont Font object
      *
@@ -245,7 +248,7 @@ class Font
     public static function calculateColumnWidth(\PhpOffice\PhpSpreadsheet\Style\Font $font, $cellText = '', $rotation = 0, \PhpOffice\PhpSpreadsheet\Style\Font $defaultFont = null)
     {
         // If it is rich text, use plain text
-        if ($cellText instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+        if ($cellText instanceof RichText) {
             $cellText = $cellText->getPlainText();
         }
 
@@ -268,7 +271,7 @@ class Font
                 // Width of text in pixels excl. padding
                 // and addition because Excel adds some padding, just use approx width of 'n' glyph
                 $columnWidth = self::getTextWidthPixelsExact($cellText, $font, $rotation) + $columnWidthAdjust;
-            } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+            } catch (PhpSpreadsheetException $e) {
                 $approximate = true;
             }
         }
@@ -294,14 +297,14 @@ class Font
      * @param \PhpOffice\PhpSpreadsheet\Style\Font
      * @param int $rotation
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return int
      */
     public static function getTextWidthPixelsExact($text, \PhpOffice\PhpSpreadsheet\Style\Font $font, $rotation = 0)
     {
         if (!function_exists('imagettfbbox')) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('GD library needs to be enabled');
+            throw new PhpSpreadsheetException('GD library needs to be enabled');
         }
 
         // font size should really be supplied in pixels in GD2,
@@ -421,7 +424,7 @@ class Font
     public static function getTrueTypeFontFileFromFont($font)
     {
         if (!file_exists(self::$trueTypeFontPath) || !is_dir(self::$trueTypeFontPath)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Valid directory to TrueType Font files not specified');
+            throw new PhpSpreadsheetException('Valid directory to TrueType Font files not specified');
         }
 
         $name = $font->getName();
@@ -510,7 +513,7 @@ class Font
                 );
                 break;
             default:
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Unknown font name "' . $name . '". Cannot map to TrueType font file');
+                throw new PhpSpreadsheetException('Unknown font name "' . $name . '". Cannot map to TrueType font file');
                 break;
         }
 
@@ -518,7 +521,7 @@ class Font
 
         // Check if file actually exists
         if (!file_exists($fontFile)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('TrueType Font file not found');
+            throw new PhpSpreadsheetException('TrueType Font file not found');
         }
 
         return $fontFile;
diff --git a/src/PhpSpreadsheet/Shared/JAMA/CholeskyDecomposition.php b/src/PhpSpreadsheet/Shared/JAMA/CholeskyDecomposition.php
index 99d20d8f..99c27711 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/CholeskyDecomposition.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/CholeskyDecomposition.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\JAMA;
 
+use PhpOffice\PhpSpreadsheet\Calculation\Exception as CalculationException;
+
 /**
  *    Cholesky decomposition class.
  *
@@ -137,8 +139,8 @@ class CholeskyDecomposition
 
                 return new Matrix($X, $this->m, $nx);
             }
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(JAMAError(MatrixSPDException));
+            throw new CalculationException(JAMAError(MatrixSPDException));
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(JAMAError(MATRIX_DIMENSION_EXCEPTION));
+        throw new CalculationException(JAMAError(MATRIX_DIMENSION_EXCEPTION));
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php b/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
index bf4b1636..624e39f1 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/LUDecomposition.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\JAMA;
 
+use PhpOffice\PhpSpreadsheet\Calculation\Exception as CalculationException;
+
 /**
  *    For an m-by-n matrix A with m >= n, the LU decomposition is an m-by-n
  *    unit lower triangular matrix L, an n-by-n upper triangular matrix U,
@@ -124,7 +126,7 @@ class LUDecomposition
                 }
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(Matrix::ARGUMENT_TYPE_EXCEPTION);
+            throw new CalculationException(Matrix::ARGUMENT_TYPE_EXCEPTION);
         }
     }
 
@@ -233,7 +235,7 @@ class LUDecomposition
 
             return $d;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(Matrix::MATRIX_DIMENSION_EXCEPTION);
+        throw new CalculationException(Matrix::MATRIX_DIMENSION_EXCEPTION);
     }
 
     //    function det()
@@ -243,8 +245,8 @@ class LUDecomposition
      *
      * @param $B a Matrix with as many rows as A and any number of columns
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Calculation\Exception illegalArgumentException Matrix row dimensions must agree
-     * @throws \PhpOffice\PhpSpreadsheet\Calculation\Exception runtimeException  Matrix is singular
+     * @throws CalculationException illegalArgumentException Matrix row dimensions must agree
+     * @throws CalculationException runtimeException  Matrix is singular
      *
      * @return X so that L*U*X = B(piv,:)
      */
@@ -277,8 +279,8 @@ class LUDecomposition
 
                 return $X;
             }
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::MATRIX_SINGULAR_EXCEPTION);
+            throw new CalculationException(self::MATRIX_SINGULAR_EXCEPTION);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::MATRIX_SQUARE_EXCEPTION);
+        throw new CalculationException(self::MATRIX_SQUARE_EXCEPTION);
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
index c1e096dc..e9ec3d06 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/Matrix.php
@@ -13,6 +13,10 @@ namespace PhpOffice\PhpSpreadsheet\Shared\JAMA;
  *    @license PHP v3.0
  *    @see http://math.nist.gov/javanumerics/jama/
  */
+use PhpOffice\PhpSpreadsheet\Calculation\Exception as CalculationException;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 class Matrix
 {
     const POLYMORPHIC_ARGUMENT_EXCEPTION = 'Invalid argument pattern for polymorphic function.';
@@ -86,15 +90,15 @@ class Matrix
                             }
                         }
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARRAY_LENGTH_EXCEPTION);
+                        throw new CalculationException(self::ARRAY_LENGTH_EXCEPTION);
                     }
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+            throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
         }
     }
 
@@ -167,12 +171,12 @@ class Matrix
                     if ($i0 >= 0) {
                         $m = $this->m - $i0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     if ($j0 >= 0) {
                         $n = $this->n - $j0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     $R = new self($m, $n);
                     for ($i = $i0; $i < $this->m; ++$i) {
@@ -189,12 +193,12 @@ class Matrix
                     if (($iF > $i0) && ($this->m >= $iF) && ($i0 >= 0)) {
                         $m = $iF - $i0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     if (($jF > $j0) && ($this->n >= $jF) && ($j0 >= 0)) {
                         $n = $jF - $j0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     $R = new self($m + 1, $n + 1);
                     for ($i = $i0; $i <= $iF; ++$i) {
@@ -211,12 +215,12 @@ class Matrix
                     if (count($RL) > 0) {
                         $m = count($RL);
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     if (count($CL) > 0) {
                         $n = count($CL);
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     $R = new self($m, $n);
                     for ($i = 0; $i < $m; ++$i) {
@@ -233,12 +237,12 @@ class Matrix
                     if (($iF > $i0) && ($this->m >= $iF) && ($i0 >= 0)) {
                         $m = $iF - $i0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     if (count($CL) > 0) {
                         $n = count($CL);
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     $R = new self($m, $n);
                     for ($i = $i0; $i < $iF; ++$i) {
@@ -255,12 +259,12 @@ class Matrix
                     if (count($RL) > 0) {
                         $m = count($RL);
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     if (($jF >= $j0) && ($this->n >= $jF) && ($j0 >= 0)) {
                         $n = $jF - $j0;
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_BOUNDS_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_BOUNDS_EXCEPTION);
                     }
                     $R = new self($m, $n + 1);
                     for ($i = 0; $i < $m; ++$i) {
@@ -272,11 +276,11 @@ class Matrix
                     return $R;
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+            throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
         }
     }
 
@@ -295,9 +299,9 @@ class Matrix
             if (($this->m == $B->getRowDimension()) && ($this->n == $B->getColumnDimension())) {
                 return true;
             }
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::MATRIX_DIMENSION_EXCEPTION);
+            throw new CalculationException(self::MATRIX_DIMENSION_EXCEPTION);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
     }
 
     //    function checkMatrixDimensions()
@@ -376,7 +380,7 @@ class Matrix
 
             return $this->getMatrix($i0, 0, $i0 + 1, $this->n);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
     }
 
     /**
@@ -398,7 +402,7 @@ class Matrix
 
             return $this->getMatrix(0, $j0, $this->m, $j0 + 1);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
     }
 
     /**
@@ -470,14 +474,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -489,7 +493,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -511,14 +515,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -528,23 +532,23 @@ class Matrix
                     $value = $M->get($i, $j);
                     if ((is_string($this->A[$i][$j])) && (strlen($this->A[$i][$j]) > 0) && (!is_numeric($this->A[$i][$j]))) {
                         $this->A[$i][$j] = trim($this->A[$i][$j], '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
+                        $validValues &= StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
                     }
                     if ((is_string($value)) && (strlen($value) > 0) && (!is_numeric($value))) {
                         $value = trim($value, '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($value);
+                        $validValues &= StringHelper::convertToNumberIfFraction($value);
                     }
                     if ($validValues) {
                         $this->A[$i][$j] += $value;
                     } else {
-                        $this->A[$i][$j] = \PhpOffice\PhpSpreadsheet\Calculation\Functions::NAN();
+                        $this->A[$i][$j] = Functions::NAN();
                     }
                 }
             }
 
             return $this;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -566,14 +570,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -585,7 +589,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -607,14 +611,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -624,23 +628,23 @@ class Matrix
                     $value = $M->get($i, $j);
                     if ((is_string($this->A[$i][$j])) && (strlen($this->A[$i][$j]) > 0) && (!is_numeric($this->A[$i][$j]))) {
                         $this->A[$i][$j] = trim($this->A[$i][$j], '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
+                        $validValues &= StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
                     }
                     if ((is_string($value)) && (strlen($value) > 0) && (!is_numeric($value))) {
                         $value = trim($value, '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($value);
+                        $validValues &= StringHelper::convertToNumberIfFraction($value);
                     }
                     if ($validValues) {
                         $this->A[$i][$j] -= $value;
                     } else {
-                        $this->A[$i][$j] = \PhpOffice\PhpSpreadsheet\Calculation\Functions::NAN();
+                        $this->A[$i][$j] = Functions::NAN();
                     }
                 }
             }
 
             return $this;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -663,14 +667,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -682,7 +686,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -705,14 +709,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -722,23 +726,23 @@ class Matrix
                     $value = $M->get($i, $j);
                     if ((is_string($this->A[$i][$j])) && (strlen($this->A[$i][$j]) > 0) && (!is_numeric($this->A[$i][$j]))) {
                         $this->A[$i][$j] = trim($this->A[$i][$j], '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
+                        $validValues &= StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
                     }
                     if ((is_string($value)) && (strlen($value) > 0) && (!is_numeric($value))) {
                         $value = trim($value, '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($value);
+                        $validValues &= StringHelper::convertToNumberIfFraction($value);
                     }
                     if ($validValues) {
                         $this->A[$i][$j] *= $value;
                     } else {
-                        $this->A[$i][$j] = \PhpOffice\PhpSpreadsheet\Calculation\Functions::NAN();
+                        $this->A[$i][$j] = Functions::NAN();
                     }
                 }
             }
 
             return $this;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -761,14 +765,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -778,11 +782,11 @@ class Matrix
                     $value = $M->get($i, $j);
                     if ((is_string($this->A[$i][$j])) && (strlen($this->A[$i][$j]) > 0) && (!is_numeric($this->A[$i][$j]))) {
                         $this->A[$i][$j] = trim($this->A[$i][$j], '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
+                        $validValues &= StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
                     }
                     if ((is_string($value)) && (strlen($value) > 0) && (!is_numeric($value))) {
                         $value = trim($value, '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($value);
+                        $validValues &= StringHelper::convertToNumberIfFraction($value);
                     }
                     if ($validValues) {
                         if ($value == 0) {
@@ -792,14 +796,14 @@ class Matrix
                             $M->set($i, $j, $this->A[$i][$j] / $value);
                         }
                     } else {
-                        $M->set($i, $j, \PhpOffice\PhpSpreadsheet\Calculation\Functions::NAN());
+                        $M->set($i, $j, Functions::NAN());
                     }
                 }
             }
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -822,14 +826,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -841,7 +845,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -864,14 +868,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -883,7 +887,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -906,14 +910,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -925,7 +929,7 @@ class Matrix
 
             return $M;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -947,7 +951,7 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $B = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     if ($this->n == $B->m) {
                         $C = new self($this->m, $B->n);
@@ -967,7 +971,7 @@ class Matrix
 
                         return $C;
                     }
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(JAMAError(MatrixDimensionMismatch));
+                    throw new CalculationException(JAMAError(MatrixDimensionMismatch));
                 case 'array':
                     $B = new self($args[0]);
                     if ($this->n == $B->m) {
@@ -984,7 +988,7 @@ class Matrix
 
                         return $C;
                     }
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(JAMAError(MatrixDimensionMismatch));
+                    throw new CalculationException(JAMAError(MatrixDimensionMismatch));
                 case 'integer':
                     $C = new self($this->A);
                     for ($i = 0; $i < $C->m; ++$i) {
@@ -1013,10 +1017,10 @@ class Matrix
 
                     return $C;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+            throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
         }
     }
 
@@ -1039,14 +1043,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -1056,23 +1060,23 @@ class Matrix
                     $value = $M->get($i, $j);
                     if ((is_string($this->A[$i][$j])) && (strlen($this->A[$i][$j]) > 0) && (!is_numeric($this->A[$i][$j]))) {
                         $this->A[$i][$j] = trim($this->A[$i][$j], '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
+                        $validValues &= StringHelper::convertToNumberIfFraction($this->A[$i][$j]);
                     }
                     if ((is_string($value)) && (strlen($value) > 0) && (!is_numeric($value))) {
                         $value = trim($value, '"');
-                        $validValues &= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertToNumberIfFraction($value);
+                        $validValues &= StringHelper::convertToNumberIfFraction($value);
                     }
                     if ($validValues) {
                         $this->A[$i][$j] = pow($this->A[$i][$j], $value);
                     } else {
-                        $this->A[$i][$j] = \PhpOffice\PhpSpreadsheet\Calculation\Functions::NAN();
+                        $this->A[$i][$j] = Functions::NAN();
                     }
                 }
             }
 
             return $this;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
@@ -1094,14 +1098,14 @@ class Matrix
                     if ($args[0] instanceof self) {
                         $M = $args[0];
                     } else {
-                        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::ARGUMENT_TYPE_EXCEPTION);
+                        throw new CalculationException(self::ARGUMENT_TYPE_EXCEPTION);
                     }
                     break;
                 case 'array':
                     $M = new self($args[0]);
                     break;
                 default:
-                    throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+                    throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
                     break;
             }
             $this->checkMatrixDimensions($M);
@@ -1113,7 +1117,7 @@ class Matrix
 
             return $this;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
+        throw new CalculationException(self::POLYMORPHIC_ARGUMENT_EXCEPTION);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php b/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
index 21644dab..55beef8b 100644
--- a/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
+++ b/src/PhpSpreadsheet/Shared/JAMA/QRDecomposition.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\JAMA;
 
+use PhpOffice\PhpSpreadsheet\Calculation\Exception as CalculationException;
+
 /**
  *    For an m-by-n matrix A with m >= n, the QR decomposition is an m-by-n
  *    orthogonal matrix Q and an n-by-n upper triangular matrix R so that
@@ -95,7 +97,7 @@ class QRDecomposition
                 $this->Rdiag[$k] = -$nrm;
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(Matrix::ARGUMENT_TYPE_EXCEPTION);
+            throw new CalculationException(Matrix::ARGUMENT_TYPE_EXCEPTION);
         }
     }
 
@@ -246,8 +248,8 @@ class QRDecomposition
 
                 return $X->getMatrix(0, $this->n - 1, 0, $nx);
             }
-            throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(self::MATRIX_RANK_EXCEPTION);
+            throw new CalculationException(self::MATRIX_RANK_EXCEPTION);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Calculation\Exception(Matrix::MATRIX_DIMENSION_EXCEPTION);
+        throw new CalculationException(Matrix::MATRIX_DIMENSION_EXCEPTION);
     }
 }
diff --git a/src/PhpSpreadsheet/Shared/OLE.php b/src/PhpSpreadsheet/Shared/OLE.php
index a2763f72..4f293659 100644
--- a/src/PhpSpreadsheet/Shared/OLE.php
+++ b/src/PhpSpreadsheet/Shared/OLE.php
@@ -26,6 +26,9 @@ namespace PhpOffice\PhpSpreadsheet\Shared;
 * OLE_ChainedBlockStream::stream_open().
 * @var  array
 */
+use PhpOffice\PhpSpreadsheet\Reader\Exception as ReaderException;
+use PhpOffice\PhpSpreadsheet\Shared\OLE\ChainedBlockStream;
+
 $GLOBALS['_OLE_INSTANCES'] = [];
 
 /**
@@ -101,7 +104,7 @@ class OLE
      *
      * @param string $file
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Reader\Exception
+     * @throws ReaderException
      *
      * @return bool true on success, PEAR_Error on failure
      */
@@ -109,18 +112,18 @@ class OLE
     {
         $fh = fopen($file, 'r');
         if (!$fh) {
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception("Can't open file $file");
+            throw new ReaderException("Can't open file $file");
         }
         $this->_file_handle = $fh;
 
         $signature = fread($fh, 8);
         if ("\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1" != $signature) {
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception("File doesn't seem to be an OLE container.");
+            throw new ReaderException("File doesn't seem to be an OLE container.");
         }
         fseek($fh, 28);
         if (fread($fh, 2) != "\xFE\xFF") {
             // This shouldn't be a problem in practice
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception('Only Little-Endian encoding is supported.');
+            throw new ReaderException('Only Little-Endian encoding is supported.');
         }
         // Size of blocks and short blocks in bytes
         $this->bigBlockSize = pow(2, self::_readInt2($fh));
@@ -212,7 +215,7 @@ class OLE
     {
         static $isRegistered = false;
         if (!$isRegistered) {
-            stream_wrapper_register('ole-chainedblockstream', \PhpOffice\PhpSpreadsheet\Shared\OLE\ChainedBlockStream::class);
+            stream_wrapper_register('ole-chainedblockstream', ChainedBlockStream::class);
             $isRegistered = true;
         }
 
diff --git a/src/PhpSpreadsheet/Shared/OLE/PPS.php b/src/PhpSpreadsheet/Shared/OLE/PPS.php
index fdc3a879..c5b91999 100644
--- a/src/PhpSpreadsheet/Shared/OLE/PPS.php
+++ b/src/PhpSpreadsheet/Shared/OLE/PPS.php
@@ -20,6 +20,7 @@ namespace PhpOffice\PhpSpreadsheet\Shared\OLE;
 // | Based on OLE::Storage_Lite by Kawai, Takanori                        |
 // +----------------------------------------------------------------------+
 //
+use PhpOffice\PhpSpreadsheet\Shared\OLE;
 
 /**
  * Class for creating PPS's for OLE containers.
@@ -188,8 +189,8 @@ class PPS
             . "\xc0\x00\x00\x00"                  // 92
             . "\x00\x00\x00\x46"                  // 96 // Seems to be ok only for Root
             . "\x00\x00\x00\x00"                  // 100
-            . \PhpOffice\PhpSpreadsheet\Shared\OLE::localDateToOLE($this->Time1st)          // 108
-            . \PhpOffice\PhpSpreadsheet\Shared\OLE::localDateToOLE($this->Time2nd)          // 116
+            . OLE::localDateToOLE($this->Time1st)          // 108
+            . OLE::localDateToOLE($this->Time2nd)          // 116
             . pack('V', isset($this->startBlock) ? $this->startBlock : 0)  // 120
             . pack('V', $this->Size)               // 124
             . pack('V', 0); // 128
diff --git a/src/PhpSpreadsheet/Shared/OLE/PPS/File.php b/src/PhpSpreadsheet/Shared/OLE/PPS/File.php
index 1df6c73f..ffaf7e0c 100644
--- a/src/PhpSpreadsheet/Shared/OLE/PPS/File.php
+++ b/src/PhpSpreadsheet/Shared/OLE/PPS/File.php
@@ -20,6 +20,8 @@ namespace PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
 // | Based on OLE::Storage_Lite by Kawai, Takanori                        |
 // +----------------------------------------------------------------------+
 //
+use PhpOffice\PhpSpreadsheet\Shared\OLE;
+use PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
 
 /**
  * Class for creating File PPS's for OLE containers.
@@ -28,7 +30,7 @@ namespace PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
  *
  * @category PhpSpreadsheet
  */
-class File extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
+class File extends PPS
 {
     /**
      * The constructor.
@@ -39,7 +41,7 @@ class File extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
      */
     public function __construct($name)
     {
-        parent::__construct(null, $name, \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_FILE, null, null, null, null, null, '', []);
+        parent::__construct(null, $name, OLE::OLE_PPS_TYPE_FILE, null, null, null, null, null, '', []);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Shared/OLE/PPS/Root.php b/src/PhpSpreadsheet/Shared/OLE/PPS/Root.php
index 00b5710e..7e411397 100644
--- a/src/PhpSpreadsheet/Shared/OLE/PPS/Root.php
+++ b/src/PhpSpreadsheet/Shared/OLE/PPS/Root.php
@@ -20,6 +20,9 @@ namespace PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
 // | Based on OLE::Storage_Lite by Kawai, Takanori                        |
 // +----------------------------------------------------------------------+
 //
+use PhpOffice\PhpSpreadsheet\Shared\OLE;
+use PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
 /**
  * Class for creating Root PPS's for OLE containers.
@@ -28,7 +31,7 @@ namespace PhpOffice\PhpSpreadsheet\Shared\OLE\PPS;
  *
  * @category PhpSpreadsheet
  */
-class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
+class Root extends PPS
 {
     /**
      * Directory for temporary files.
@@ -46,7 +49,7 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
     {
         $this->_tempDir = \PhpOffice\PhpSpreadsheet\Shared\File::sysGetTempDir();
 
-        parent::__construct(null, \PhpOffice\PhpSpreadsheet\Shared\OLE::ascToUcs('Root Entry'), \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_ROOT, null, null, null, $time_1st, $time_2nd, null, $raChild);
+        parent::__construct(null, OLE::ascToUcs('Root Entry'), OLE::OLE_PPS_TYPE_ROOT, null, null, null, $time_1st, $time_2nd, null, $raChild);
     }
 
     /**
@@ -58,7 +61,7 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
      *
      * @param string|resource $filename the name of the file or stream where to save the OLE container
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return bool true on success
      */
@@ -83,17 +86,17 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
             $this->_tmp_filename = tempnam($this->tempDirectory, 'OLE_PPS_Root');
             $this->_FILEH_ = fopen($this->_tmp_filename, 'w+b');
             if ($this->_FILEH_ == false) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Can't create temporary file.");
+                throw new WriterException("Can't create temporary file.");
             }
         } else {
             $this->_FILEH_ = fopen($filename, 'wb');
         }
         if ($this->_FILEH_ == false) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Can't open $filename. It may be in use or protected.");
+            throw new WriterException("Can't open $filename. It may be in use or protected.");
         }
         // Make an array of PPS's (for Save)
         $aList = [];
-        \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS::_savePpsSetPnt($aList, [$this]);
+        PPS::_savePpsSetPnt($aList, [$this]);
         // calculate values for header
         list($iSBDcnt, $iBBcnt, $iPPScnt) = $this->_calcSize($aList); //, $rhInfo);
         // Save Header
@@ -131,9 +134,9 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
         $iSBcnt = 0;
         $iCount = count($raList);
         for ($i = 0; $i < $iCount; ++$i) {
-            if ($raList[$i]->Type == \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_FILE) {
+            if ($raList[$i]->Type == OLE::OLE_PPS_TYPE_FILE) {
                 $raList[$i]->Size = $raList[$i]->getDataLen();
-                if ($raList[$i]->Size < \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_DATA_SIZE_SMALL) {
+                if ($raList[$i]->Size < OLE::OLE_DATA_SIZE_SMALL) {
                     $iSBcnt += floor($raList[$i]->Size / $this->_SMALL_BLOCK_SIZE)
                                   + (($raList[$i]->Size % $this->_SMALL_BLOCK_SIZE) ? 1 : 0);
                 } else {
@@ -143,12 +146,12 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
             }
         }
         $iSmallLen = $iSBcnt * $this->_SMALL_BLOCK_SIZE;
-        $iSlCnt = floor($this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE);
+        $iSlCnt = floor($this->_BIG_BLOCK_SIZE / OLE::OLE_LONG_INT_SIZE);
         $iSBDcnt = floor($iSBcnt / $iSlCnt) + (($iSBcnt % $iSlCnt) ? 1 : 0);
         $iBBcnt += (floor($iSmallLen / $this->_BIG_BLOCK_SIZE) +
                       (($iSmallLen % $this->_BIG_BLOCK_SIZE) ? 1 : 0));
         $iCnt = count($raList);
-        $iBdCnt = $this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_SIZE;
+        $iBdCnt = $this->_BIG_BLOCK_SIZE / OLE::OLE_PPS_SIZE;
         $iPPScnt = (floor($iCnt / $iBdCnt) + (($iCnt % $iBdCnt) ? 1 : 0));
 
         return [$iSBDcnt, $iBBcnt, $iPPScnt];
@@ -182,8 +185,8 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
         $FILE = $this->_FILEH_;
 
         // Calculate Basic Setting
-        $iBlCnt = $this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE;
-        $i1stBdL = ($this->_BIG_BLOCK_SIZE - 0x4C) / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE;
+        $iBlCnt = $this->_BIG_BLOCK_SIZE / OLE::OLE_LONG_INT_SIZE;
+        $i1stBdL = ($this->_BIG_BLOCK_SIZE - 0x4C) / OLE::OLE_LONG_INT_SIZE;
 
         $iBdExL = 0;
         $iAll = $iBBcnt + $iPPScnt + $iSBDcnt;
@@ -263,9 +266,9 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
         // cycle through PPS's
         $iCount = count($raList);
         for ($i = 0; $i < $iCount; ++$i) {
-            if ($raList[$i]->Type != \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_DIR) {
+            if ($raList[$i]->Type != OLE::OLE_PPS_TYPE_DIR) {
                 $raList[$i]->Size = $raList[$i]->getDataLen();
-                if (($raList[$i]->Size >= \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_DATA_SIZE_SMALL) || (($raList[$i]->Type == \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_ROOT) && isset($raList[$i]->_data))) {
+                if (($raList[$i]->Size >= OLE::OLE_DATA_SIZE_SMALL) || (($raList[$i]->Type == OLE::OLE_PPS_TYPE_ROOT) && isset($raList[$i]->_data))) {
                     fwrite($FILE, $raList[$i]->_data);
 
                     if ($raList[$i]->Size % $this->_BIG_BLOCK_SIZE) {
@@ -295,11 +298,11 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
         $iCount = count($raList);
         for ($i = 0; $i < $iCount; ++$i) {
             // Make SBD, small data string
-            if ($raList[$i]->Type == \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_TYPE_FILE) {
+            if ($raList[$i]->Type == OLE::OLE_PPS_TYPE_FILE) {
                 if ($raList[$i]->Size <= 0) {
                     continue;
                 }
-                if ($raList[$i]->Size < \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_DATA_SIZE_SMALL) {
+                if ($raList[$i]->Size < OLE::OLE_DATA_SIZE_SMALL) {
                     $iSmbCnt = floor($raList[$i]->Size / $this->_SMALL_BLOCK_SIZE)
                                   + (($raList[$i]->Size % $this->_SMALL_BLOCK_SIZE) ? 1 : 0);
                     // Add to SBD
@@ -320,7 +323,7 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
                 }
             }
         }
-        $iSbCnt = floor($this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE);
+        $iSbCnt = floor($this->_BIG_BLOCK_SIZE / OLE::OLE_LONG_INT_SIZE);
         if ($iSmBlk % $iSbCnt) {
             $iB = $iSbCnt - ($iSmBlk % $iSbCnt);
             for ($i = 0; $i < $iB; ++$i) {
@@ -345,9 +348,9 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
         }
         // Adjust for Block
         $iCnt = count($raList);
-        $iBCnt = $this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_SIZE;
+        $iBCnt = $this->_BIG_BLOCK_SIZE / OLE::OLE_PPS_SIZE;
         if ($iCnt % $iBCnt) {
-            fwrite($this->_FILEH_, str_repeat("\x00", ($iBCnt - ($iCnt % $iBCnt)) * \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_PPS_SIZE));
+            fwrite($this->_FILEH_, str_repeat("\x00", ($iBCnt - ($iCnt % $iBCnt)) * OLE::OLE_PPS_SIZE));
         }
     }
 
@@ -362,8 +365,8 @@ class Root extends \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS
     {
         $FILE = $this->_FILEH_;
         // Calculate Basic Setting
-        $iBbCnt = $this->_BIG_BLOCK_SIZE / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE;
-        $i1stBdL = ($this->_BIG_BLOCK_SIZE - 0x4C) / \PhpOffice\PhpSpreadsheet\Shared\OLE::OLE_LONG_INT_SIZE;
+        $iBbCnt = $this->_BIG_BLOCK_SIZE / OLE::OLE_LONG_INT_SIZE;
+        $i1stBdL = ($this->_BIG_BLOCK_SIZE - 0x4C) / OLE::OLE_LONG_INT_SIZE;
 
         $iBdExL = 0;
         $iAll = $iBsize + $iPpsCnt + $iSbdSize;
diff --git a/src/PhpSpreadsheet/Shared/OLERead.php b/src/PhpSpreadsheet/Shared/OLERead.php
index 515a1fa3..3c36561e 100644
--- a/src/PhpSpreadsheet/Shared/OLERead.php
+++ b/src/PhpSpreadsheet/Shared/OLERead.php
@@ -26,6 +26,8 @@ namespace PhpOffice\PhpSpreadsheet\Shared;
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
 
+use PhpOffice\PhpSpreadsheet\Reader\Exception as ReaderException;
+
 defined('IDENTIFIER_OLE') ||
     define('IDENTIFIER_OLE', pack('CCCCCCCC', 0xd0, 0xcf, 0x11, 0xe0, 0xa1, 0xb1, 0x1a, 0xe1));
 
@@ -71,7 +73,7 @@ class OLERead
      *
      * @param $pFilename string Filename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Reader\Exception
+     * @throws ReaderException
      */
     public function read($pFilename)
     {
@@ -83,7 +85,7 @@ class OLERead
 
         // Check OLE identifier
         if ($this->data != self::IDENTIFIER_OLE) {
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception('The filename ' . $pFilename . ' is not recognised as an OLE file');
+            throw new ReaderException('The filename ' . $pFilename . ' is not recognised as an OLE file');
         }
 
         // Get the file data
@@ -303,10 +305,10 @@ class OLERead
     {
         if (trim($data) == '') {
             // No data provided
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception('Parameter data is empty.');
+            throw new ReaderException('Parameter data is empty.');
         } elseif ($pos < 0) {
             // Invalid position
-            throw new \PhpOffice\PhpSpreadsheet\Reader\Exception('Parameter pos=' . $pos . ' is invalid.');
+            throw new ReaderException('Parameter pos=' . $pos . ' is invalid.');
         }
 
         $len = strlen($data);
diff --git a/src/PhpSpreadsheet/Shared/StringHelper.php b/src/PhpSpreadsheet/Shared/StringHelper.php
index b1d51250..b7e8e568 100644
--- a/src/PhpSpreadsheet/Shared/StringHelper.php
+++ b/src/PhpSpreadsheet/Shared/StringHelper.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -588,7 +590,7 @@ class StringHelper
         if (preg_match('/^' . self::STRING_REGEXP_FRACTION . '$/i', $operand, $match)) {
             $sign = ($match[1] == '-') ? '-' : '+';
             $fractionFormula = '=' . $sign . $match[2] . $sign . $match[3];
-            $operand = \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->_calculateFormulaValue($fractionFormula);
+            $operand = Calculation::getInstance()->_calculateFormulaValue($fractionFormula);
 
             return true;
         }
@@ -621,7 +623,7 @@ class StringHelper
     }
 
     /**
-     * Set the decimal separator. Only used by \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString()
+     * Set the decimal separator. Only used by NumberFormat::toFormattedString()
      * to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
      *
      * @param string $pValue Character for decimal separator
@@ -654,7 +656,7 @@ class StringHelper
     }
 
     /**
-     * Set the thousands separator. Only used by \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString()
+     * Set the thousands separator. Only used by NumberFormat::toFormattedString()
      * to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
      *
      * @param string $pValue Character for thousands separator
@@ -692,7 +694,7 @@ class StringHelper
     }
 
     /**
-     * Set the currency code. Only used by \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString()
+     * Set the currency code. Only used by NumberFormat::toFormattedString()
      *        to format output by \PhpOffice\PhpSpreadsheet\Writer\Html and \PhpOffice\PhpSpreadsheet\Writer\Pdf.
      *
      * @param string $pValue Character for currency code
diff --git a/src/PhpSpreadsheet/Shared/TimeZone.php b/src/PhpSpreadsheet/Shared/TimeZone.php
index 46348cae..ac49c282 100644
--- a/src/PhpSpreadsheet/Shared/TimeZone.php
+++ b/src/PhpSpreadsheet/Shared/TimeZone.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use DateTimeZone;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -43,7 +46,7 @@ class TimeZone
      */
     private static function validateTimeZone($timezone)
     {
-        if (in_array($timezone, \DateTimeZone::listIdentifiers())) {
+        if (in_array($timezone, DateTimeZone::listIdentifiers())) {
             return true;
         }
 
@@ -85,7 +88,7 @@ class TimeZone
      * @param string $timezone The timezone for finding the adjustment to UST
      * @param int $timestamp PHP date/time value
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return int Number of seconds for timezone adjustment
      */
@@ -93,7 +96,7 @@ class TimeZone
     {
         if ($timezone !== null) {
             if (!self::validateTimezone($timezone)) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid timezone ' . $timezone);
+                throw new PhpSpreadsheetException('Invalid timezone ' . $timezone);
             }
         } else {
             $timezone = self::$timezone;
@@ -103,7 +106,7 @@ class TimeZone
             return 0;
         }
 
-        $objTimezone = new \DateTimeZone($timezone);
+        $objTimezone = new DateTimeZone($timezone);
         $transitions = $objTimezone->getTransitions($timestamp, $timestamp);
 
         return (count($transitions) > 0) ? $transitions[0]['offset'] : 0;
diff --git a/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php b/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
index 822a3e70..24d2bd8a 100644
--- a/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
+++ b/src/PhpSpreadsheet/Shared/Trend/PolynomialBestFit.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared\Trend;
 
+use PhpOffice\PhpSpreadsheet\Shared\JAMA\Matrix;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
diff --git a/src/PhpSpreadsheet/Shared/Xls.php b/src/PhpSpreadsheet/Shared/Xls.php
index de7c29e5..1c8797dc 100644
--- a/src/PhpSpreadsheet/Shared/Xls.php
+++ b/src/PhpSpreadsheet/Shared/Xls.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Shared;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -31,7 +34,7 @@ class Xls
      * x is the width in intrinsic Excel units (measuring width in number of normal characters)
      * This holds for Arial 10.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet The sheet
+     * @param Worksheet $sheet The sheet
      * @param string $col The column
      *
      * @return int The width in pixels
@@ -48,15 +51,15 @@ class Xls
             // then we have column dimension with explicit width
             $columnDimension = $columnDimensions[$col];
             $width = $columnDimension->getWidth();
-            $pixelWidth = \PhpOffice\PhpSpreadsheet\Shared\Drawing::cellDimensionToPixels($width, $font);
+            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
         } elseif ($sheet->getDefaultColumnDimension()->getWidth() != -1) {
             // then we have default column dimension with explicit width
             $defaultColumnDimension = $sheet->getDefaultColumnDimension();
             $width = $defaultColumnDimension->getWidth();
-            $pixelWidth = \PhpOffice\PhpSpreadsheet\Shared\Drawing::cellDimensionToPixels($width, $font);
+            $pixelWidth = Drawing::cellDimensionToPixels($width, $font);
         } else {
             // we don't even have any default column dimension. Width depends on default font
-            $pixelWidth = \PhpOffice\PhpSpreadsheet\Shared\Font::getDefaultColumnWidthByFont($font, true);
+            $pixelWidth = Font::getDefaultColumnWidthByFont($font, true);
         }
 
         // now find the effective column width in pixels
@@ -74,7 +77,7 @@ class Xls
      * the relationship is: y = 4/3x. If the height hasn't been set by the user we
      * use the default value. If the row is hidden we use a value of zero.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet The sheet
+     * @param Worksheet $sheet The sheet
      * @param int $row The row index (1-based)
      *
      * @return int The width in pixels
@@ -96,11 +99,11 @@ class Xls
             // then we have a default row dimension with explicit height
             $defaultRowDimension = $sheet->getDefaultRowDimension();
             $rowHeight = $defaultRowDimension->getRowHeight();
-            $pixelRowHeight = \PhpOffice\PhpSpreadsheet\Shared\Drawing::pointsToPixels($rowHeight);
+            $pixelRowHeight = Drawing::pointsToPixels($rowHeight);
         } else {
             // we don't even have any default row dimension. Height depends on default font
-            $pointRowHeight = \PhpOffice\PhpSpreadsheet\Shared\Font::getDefaultRowHeightByFont($font);
-            $pixelRowHeight = \PhpOffice\PhpSpreadsheet\Shared\Font::fontSizeToPixels($pointRowHeight);
+            $pointRowHeight = Font::getDefaultRowHeightByFont($font);
+            $pixelRowHeight = Font::fontSizeToPixels($pointRowHeight);
         }
 
         // now find the effective row height in pixels
@@ -117,7 +120,7 @@ class Xls
      * Get the horizontal distance in pixels between two anchors
      * The distanceX is found as sum of all the spanning columns widths minus correction for the two offsets.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet
+     * @param Worksheet $sheet
      * @param string $startColumn
      * @param int $startOffsetX Offset within start cell measured in 1/1024 of the cell width
      * @param string $endColumn
@@ -125,15 +128,15 @@ class Xls
      *
      * @return int Horizontal measured in pixels
      */
-    public static function getDistanceX(\PhpOffice\PhpSpreadsheet\Worksheet $sheet, $startColumn = 'A', $startOffsetX = 0, $endColumn = 'A', $endOffsetX = 0)
+    public static function getDistanceX(Worksheet $sheet, $startColumn = 'A', $startOffsetX = 0, $endColumn = 'A', $endOffsetX = 0)
     {
         $distanceX = 0;
 
         // add the widths of the spanning columns
-        $startColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($startColumn) - 1; // 1-based
-        $endColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($endColumn) - 1; // 1-based
+        $startColumnIndex = Cell::columnIndexFromString($startColumn) - 1; // 1-based
+        $endColumnIndex = Cell::columnIndexFromString($endColumn) - 1; // 1-based
         for ($i = $startColumnIndex; $i <= $endColumnIndex; ++$i) {
-            $distanceX += self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($i));
+            $distanceX += self::sizeCol($sheet, Cell::stringFromColumnIndex($i));
         }
 
         // correct for offsetX in startcell
@@ -149,7 +152,7 @@ class Xls
      * Get the vertical distance in pixels between two anchors
      * The distanceY is found as sum of all the spanning rows minus two offsets.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet
+     * @param Worksheet $sheet
      * @param int $startRow (1-based)
      * @param int $startOffsetY Offset within start cell measured in 1/256 of the cell height
      * @param int $endRow (1-based)
@@ -157,7 +160,7 @@ class Xls
      *
      * @return int Vertical distance measured in pixels
      */
-    public static function getDistanceY(\PhpOffice\PhpSpreadsheet\Worksheet $sheet, $startRow = 1, $startOffsetY = 0, $endRow = 1, $endOffsetY = 0)
+    public static function getDistanceY(Worksheet $sheet, $startRow = 1, $startOffsetY = 0, $endRow = 1, $endOffsetY = 0)
     {
         $distanceY = 0;
 
@@ -219,7 +222,7 @@ class Xls
      *               W is the width of the cell
      *               H is the height of the cell
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $sheet
+     * @param Worksheet $sheet
      * @param string $coordinates E.g. 'A1'
      * @param int $offsetX Horizontal offset in pixels
      * @param int $offsetY Vertical offset in pixels
@@ -230,8 +233,8 @@ class Xls
      */
     public static function oneAnchor2twoAnchor($sheet, $coordinates, $offsetX, $offsetY, $width, $height)
     {
-        list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($coordinates);
-        $col_start = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+        list($column, $row) = Cell::coordinateFromString($coordinates);
+        $col_start = Cell::columnIndexFromString($column) - 1;
         $row_start = $row - 1;
 
         $x1 = $offsetX;
@@ -242,7 +245,7 @@ class Xls
         $row_end = $row_start; // Row containing bottom right corner of object
 
         // Zero the specified offset if greater than the cell dimensions
-        if ($x1 >= self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start))) {
+        if ($x1 >= self::sizeCol($sheet, Cell::stringFromColumnIndex($col_start))) {
             $x1 = 0;
         }
         if ($y1 >= self::sizeRow($sheet, $row_start + 1)) {
@@ -253,8 +256,8 @@ class Xls
         $height = $height + $y1 - 1;
 
         // Subtract the underlying cell widths to find the end cell of the image
-        while ($width >= self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end))) {
-            $width -= self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end));
+        while ($width >= self::sizeCol($sheet, Cell::stringFromColumnIndex($col_end))) {
+            $width -= self::sizeCol($sheet, Cell::stringFromColumnIndex($col_end));
             ++$col_end;
         }
 
@@ -266,10 +269,10 @@ class Xls
 
         // Bitmap isn't allowed to start or finish in a hidden cell, i.e. a cell
         // with zero height or width.
-        if (self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start)) == 0) {
+        if (self::sizeCol($sheet, Cell::stringFromColumnIndex($col_start)) == 0) {
             return;
         }
-        if (self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end)) == 0) {
+        if (self::sizeCol($sheet, Cell::stringFromColumnIndex($col_end)) == 0) {
             return;
         }
         if (self::sizeRow($sheet, $row_start + 1) == 0) {
@@ -280,13 +283,13 @@ class Xls
         }
 
         // Convert the pixel values to the percentage value expected by Excel
-        $x1 = $x1 / self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start)) * 1024;
+        $x1 = $x1 / self::sizeCol($sheet, Cell::stringFromColumnIndex($col_start)) * 1024;
         $y1 = $y1 / self::sizeRow($sheet, $row_start + 1) * 256;
-        $x2 = ($width + 1) / self::sizeCol($sheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end)) * 1024; // Distance to right side of object
+        $x2 = ($width + 1) / self::sizeCol($sheet, Cell::stringFromColumnIndex($col_end)) * 1024; // Distance to right side of object
         $y2 = ($height + 1) / self::sizeRow($sheet, $row_end + 1) * 256; // Distance to bottom of object
 
-        $startCoordinates = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start) . ($row_start + 1);
-        $endCoordinates = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end) . ($row_end + 1);
+        $startCoordinates = Cell::stringFromColumnIndex($col_start) . ($row_start + 1);
+        $endCoordinates = Cell::stringFromColumnIndex($col_end) . ($row_end + 1);
 
         $twoAnchor = [
             'startCoordinates' => $startCoordinates,
diff --git a/src/PhpSpreadsheet/Style.php b/src/PhpSpreadsheet/Style.php
index 65902077..8f7f9407 100644
--- a/src/PhpSpreadsheet/Style.php
+++ b/src/PhpSpreadsheet/Style.php
@@ -184,13 +184,13 @@ class Style extends Style\Supervisor implements IComparable
      *             ),
      *             'borders' => array(
      *                 'bottom'     => array(
-     *                     'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *                     'style' => Border::BORDER_DASHDOT,
      *                     'color' => array(
      *                         'rgb' => '808080'
      *                     )
      *                 ),
      *                 'top'     => array(
-     *                     'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *                     'style' => Border::BORDER_DASHDOT,
      *                     'color' => array(
      *                         'rgb' => '808080'
      *                     )
diff --git a/src/PhpSpreadsheet/Style/Alignment.php b/src/PhpSpreadsheet/Style/Alignment.php
index 6ee25160..6ea74462 100644
--- a/src/PhpSpreadsheet/Style/Alignment.php
+++ b/src/PhpSpreadsheet/Style/Alignment.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Alignment extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Alignment extends Supervisor implements IComparable
 {
     /* Horizontal alignment styles */
     const HORIZONTAL_GENERAL = 'general';
@@ -144,7 +147,6 @@ class Alignment extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompara
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getAlignment()->applyFromArray(
      *        array(
@@ -154,11 +156,11 @@ class Alignment extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompara
      *            'wrap'            => TRUE
      *        )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Alignment
      */
@@ -287,7 +289,7 @@ class Alignment extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompara
      *
      * @param int $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Alignment
      */
@@ -307,7 +309,7 @@ class Alignment extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompara
                 $this->textRotation = $pValue;
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Text rotation should be a value between -90 and 90.');
+            throw new PhpSpreadsheetException('Text rotation should be a value between -90 and 90.');
         }
 
         return $this;
diff --git a/src/PhpSpreadsheet/Style/Border.php b/src/PhpSpreadsheet/Style/Border.php
index 9c2d8891..38246d47 100644
--- a/src/PhpSpreadsheet/Style/Border.php
+++ b/src/PhpSpreadsheet/Style/Border.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Border extends Supervisor implements IComparable
 {
     /* Border style */
     const BORDER_NONE = 'none';
@@ -107,7 +110,7 @@ class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      * Get the shared style component for the currently active cell in currently active sheet.
      * Only used for style supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
@@ -119,7 +122,7 @@ class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
             case 'inside':
             case 'outline':
             case 'vertical':
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Cannot get shared component for a pseudo-border.');
+                throw new PhpSpreadsheetException('Cannot get shared component for a pseudo-border.');
                 break;
             case 'bottom':
                 return $this->parent->getSharedComponent()->getBottom();
@@ -167,7 +170,7 @@ class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getBorders()->getTop()->applyFromArray(
      *        array(
-     *            'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *            'style' => Border::BORDER_DASHDOT,
      *            'color' => array(
      *                'rgb' => '808080'
      *            )
@@ -177,7 +180,7 @@ class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
@@ -252,7 +255,7 @@ class Border extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param Color $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
diff --git a/src/PhpSpreadsheet/Style/Borders.php b/src/PhpSpreadsheet/Style/Borders.php
index 06268d8b..bc599235 100644
--- a/src/PhpSpreadsheet/Style/Borders.php
+++ b/src/PhpSpreadsheet/Style/Borders.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Borders extends Supervisor implements IComparable
 {
     /* Diagonal directions */
     const DIAGONAL_NONE = 0;
@@ -180,18 +183,17 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getBorders()->applyFromArray(
      *         array(
      *             'bottom'     => array(
-     *                 'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *                 'style' => Border::BORDER_DASHDOT,
      *                 'color' => array(
      *                     'rgb' => '808080'
      *                 )
      *             ),
      *             'top'     => array(
-     *                 'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *                 'style' => Border::BORDER_DASHDOT,
      *                 'color' => array(
      *                     'rgb' => '808080'
      *                 )
@@ -203,18 +205,18 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getBorders()->applyFromArray(
      *         array(
      *             'allborders' => array(
-     *                 'style' => \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT,
+     *                 'style' => Border::BORDER_DASHDOT,
      *                 'color' => array(
      *                     'rgb' => '808080'
      *                 )
      *             )
      *         )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Borders
      */
@@ -305,14 +307,14 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
     /**
      * Get AllBorders (pseudo-border). Only applies to supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
     public function getAllBorders()
     {
         if (!$this->isSupervisor) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Can only get pseudo-border for supervisor.');
+            throw new PhpSpreadsheetException('Can only get pseudo-border for supervisor.');
         }
 
         return $this->allBorders;
@@ -321,14 +323,14 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
     /**
      * Get Outline (pseudo-border). Only applies to supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return bool
      */
     public function getOutline()
     {
         if (!$this->isSupervisor) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Can only get pseudo-border for supervisor.');
+            throw new PhpSpreadsheetException('Can only get pseudo-border for supervisor.');
         }
 
         return $this->outline;
@@ -337,14 +339,14 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
     /**
      * Get Inside (pseudo-border). Only applies to supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return bool
      */
     public function getInside()
     {
         if (!$this->isSupervisor) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Can only get pseudo-border for supervisor.');
+            throw new PhpSpreadsheetException('Can only get pseudo-border for supervisor.');
         }
 
         return $this->inside;
@@ -353,14 +355,14 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
     /**
      * Get Vertical (pseudo-border). Only applies to supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
     public function getVertical()
     {
         if (!$this->isSupervisor) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Can only get pseudo-border for supervisor.');
+            throw new PhpSpreadsheetException('Can only get pseudo-border for supervisor.');
         }
 
         return $this->vertical;
@@ -369,14 +371,14 @@ class Borders extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparabl
     /**
      * Get Horizontal (pseudo-border). Only applies to supervisor.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Border
      */
     public function getHorizontal()
     {
         if (!$this->isSupervisor) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Can only get pseudo-border for supervisor.');
+            throw new PhpSpreadsheetException('Can only get pseudo-border for supervisor.');
         }
 
         return $this->horizontal;
diff --git a/src/PhpSpreadsheet/Style/Color.php b/src/PhpSpreadsheet/Style/Color.php
index 3fdd6308..ec5e6ffb 100644
--- a/src/PhpSpreadsheet/Style/Color.php
+++ b/src/PhpSpreadsheet/Style/Color.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Color extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Color extends Supervisor implements IComparable
 {
     /* Colors */
     const COLOR_BLACK = 'FF000000';
@@ -141,14 +144,13 @@ class Color extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getFont()->getColor()->applyFromArray( array('rgb' => '808080') );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Color
      */
diff --git a/src/PhpSpreadsheet/Style/Conditional.php b/src/PhpSpreadsheet/Style/Conditional.php
index 84578411..7ce31c31 100644
--- a/src/PhpSpreadsheet/Style/Conditional.php
+++ b/src/PhpSpreadsheet/Style/Conditional.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+use PhpOffice\PhpSpreadsheet\Style;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +28,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Conditional implements \PhpOffice\PhpSpreadsheet\IComparable
+class Conditional implements IComparable
 {
     /* Condition types */
     const CONDITION_NONE = 'none';
@@ -92,7 +96,7 @@ class Conditional implements \PhpOffice\PhpSpreadsheet\IComparable
         $this->operatorType = self::OPERATOR_NONE;
         $this->text = null;
         $this->condition = [];
-        $this->style = new \PhpOffice\PhpSpreadsheet\Style(false, true);
+        $this->style = new Style(false, true);
     }
 
     /**
@@ -221,13 +225,13 @@ class Conditional implements \PhpOffice\PhpSpreadsheet\IComparable
     /**
      * Set Style.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style $pValue
+     * @param Style $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Conditional
      */
-    public function setStyle(\PhpOffice\PhpSpreadsheet\Style $pValue = null)
+    public function setStyle(Style $pValue = null)
     {
         $this->style = $pValue;
 
diff --git a/src/PhpSpreadsheet/Style/Fill.php b/src/PhpSpreadsheet/Style/Fill.php
index 9cbf6841..dca4ea8d 100644
--- a/src/PhpSpreadsheet/Style/Fill.php
+++ b/src/PhpSpreadsheet/Style/Fill.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Fill extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Fill extends Supervisor implements IComparable
 {
     /* Fill types */
     const FILL_NONE = 'none';
@@ -131,11 +134,10 @@ class Fill extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getFill()->applyFromArray(
      *        array(
-     *            'type'       => \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR,
+     *            'type'       => Fill::FILL_GRADIENT_LINEAR,
      *            'rotation'   => 0,
      *            'startcolor' => array(
      *                'rgb' => '000000'
@@ -145,11 +147,11 @@ class Fill extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *            )
      *        )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Fill
      */
@@ -260,7 +262,7 @@ class Fill extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param Color $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Fill
      */
@@ -294,7 +296,7 @@ class Fill extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param Color $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Fill
      */
diff --git a/src/PhpSpreadsheet/Style/Font.php b/src/PhpSpreadsheet/Style/Font.php
index 3436382a..c51a945c 100644
--- a/src/PhpSpreadsheet/Style/Font.php
+++ b/src/PhpSpreadsheet/Style/Font.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Font extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Font extends Supervisor implements IComparable
 {
     /* Underline types */
     const UNDERLINE_NONE = 'none';
@@ -156,7 +159,6 @@ class Font extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getFont()->applyFromArray(
      *        array(
@@ -170,11 +172,11 @@ class Font extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *            )
      *        )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Font
      */
@@ -524,7 +526,7 @@ class Font extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param Color $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Font
      */
diff --git a/src/PhpSpreadsheet/Style/NumberFormat.php b/src/PhpSpreadsheet/Style/NumberFormat.php
index 779fb2f9..21aaf40e 100644
--- a/src/PhpSpreadsheet/Style/NumberFormat.php
+++ b/src/PhpSpreadsheet/Style/NumberFormat.php
@@ -2,6 +2,12 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Calculation\MathTrig;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +30,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class NumberFormat extends Supervisor implements IComparable
 {
     /* Pre-defined formats */
     const FORMAT_GENERAL = 'General';
@@ -140,18 +146,17 @@ class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComp
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getNumberFormat()->applyFromArray(
      *        array(
-     *            'code' => \PhpOffice\PhpSpreadsheet\Style\NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE
+     *            'code' => NumberFormat::FORMAT_CURRENCY_EUR_SIMPLE
      *        )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return NumberFormat
      */
@@ -493,7 +498,7 @@ class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComp
         // escape any quoted characters so that DateTime format() will render them correctly
         $format = preg_replace_callback('/"(.*)"/U', ['self', 'escapeQuotesCallback'], $format);
 
-        $dateObj = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToDateTimeObject($value);
+        $dateObj = Date::excelToDateTimeObject($value);
         $value = $dateObj->format($format);
     }
 
@@ -524,7 +529,7 @@ class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComp
         $decimalLength = strlen($decimalPart);
         $decimalDivisor = pow(10, $decimalLength);
 
-        $GCD = \PhpOffice\PhpSpreadsheet\Calculation\MathTrig::GCD($decimalPart, $decimalDivisor);
+        $GCD = MathTrig::GCD($decimalPart, $decimalDivisor);
 
         $adjustedDecimalPart = $decimalPart / $GCD;
         $adjustedDecimalDivisor = $decimalDivisor / $GCD;
@@ -717,8 +722,8 @@ class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComp
                             $value = number_format(
                                 $value,
                                 strlen($right),
-                                \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getDecimalSeparator(),
-                                \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getThousandsSeparator()
+                                StringHelper::getDecimalSeparator(),
+                                StringHelper::getThousandsSeparator()
                             );
                             $value = preg_replace($number_regex, $value, $format);
                         } else {
@@ -741,7 +746,7 @@ class NumberFormat extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComp
                     $currencyCode = $m[1];
                     list($currencyCode) = explode('-', $currencyCode);
                     if ($currencyCode == '') {
-                        $currencyCode = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::getCurrencyCode();
+                        $currencyCode = StringHelper::getCurrencyCode();
                     }
                     $value = preg_replace('/\[\$([^\]]*)\]/u', $currencyCode, $value);
                 }
diff --git a/src/PhpSpreadsheet/Style/Protection.php b/src/PhpSpreadsheet/Style/Protection.php
index 848ac1be..1ad71588 100644
--- a/src/PhpSpreadsheet/Style/Protection.php
+++ b/src/PhpSpreadsheet/Style/Protection.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Style;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Style;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Protection extends Supervisor implements \PhpOffice\PhpSpreadsheet\IComparable
+class Protection extends Supervisor implements IComparable
 {
     /** Protection styles */
     const PROTECTION_INHERIT = 'inherit';
@@ -92,7 +95,6 @@ class Protection extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompar
 
     /**
      * Apply styles from array.
-     *
      * <code>
      * $spreadsheet->getActiveSheet()->getStyle('B2')->getLocked()->applyFromArray(
      *        array(
@@ -100,11 +102,11 @@ class Protection extends Supervisor implements \PhpOffice\PhpSpreadsheet\ICompar
      *            'hidden' => FALSE
      *        )
      * );
-     * </code>
+     * </code>.
      *
      * @param array $pStyles Array containing style information
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Protection
      */
diff --git a/src/PhpSpreadsheet/Style/Supervisor.php b/src/PhpSpreadsheet/Style/Supervisor.php
index d3b07929..b8c51f65 100644
--- a/src/PhpSpreadsheet/Style/Supervisor.php
+++ b/src/PhpSpreadsheet/Style/Supervisor.php
@@ -56,7 +56,7 @@ abstract class Supervisor
     /**
      * Bind parent. Only used for supervisor.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style $parent
+     * @param Style $parent
      * @param null|mixed $parentPropertyName
      *
      * @return Supervisor
diff --git a/src/PhpSpreadsheet/Worksheet.php b/src/PhpSpreadsheet/Worksheet.php
index 4a6799d3..b2278e7d 100644
--- a/src/PhpSpreadsheet/Worksheet.php
+++ b/src/PhpSpreadsheet/Worksheet.php
@@ -1657,7 +1657,7 @@ class Worksheet implements IComparable
      *
      * @param int $pColumn Numeric column coordinate of the cell (A = 0)
      * @param int $pRow Numeric row coordinate of the cell
-     * @param int $pBreak Break type (type of \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_*)
+     * @param int $pBreak Break type (type of Worksheet::BREAK_*)
      *
      * @return Worksheet
      */
diff --git a/src/PhpSpreadsheet/Worksheet/AutoFilter.php b/src/PhpSpreadsheet/Worksheet/AutoFilter.php
index a9298433..88042565 100644
--- a/src/PhpSpreadsheet/Worksheet/AutoFilter.php
+++ b/src/PhpSpreadsheet/Worksheet/AutoFilter.php
@@ -2,6 +2,14 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\DateTime;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,7 +37,7 @@ class AutoFilter
     /**
      * Autofilter Worksheet.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Worksheet
+     * @var Worksheet
      */
     private $workSheet;
 
@@ -51,9 +59,9 @@ class AutoFilter
      * Create a new AutoFilter.
      *
      * @param string $pRange Cell range (i.e. A1:E10)
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param Worksheet $pSheet
      */
-    public function __construct($pRange = '', \PhpOffice\PhpSpreadsheet\Worksheet $pSheet = null)
+    public function __construct($pRange = '', Worksheet $pSheet = null)
     {
         $this->range = $pRange;
         $this->workSheet = $pSheet;
@@ -62,7 +70,7 @@ class AutoFilter
     /**
      * Get AutoFilter Parent Worksheet.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Worksheet
+     * @return Worksheet
      */
     public function getParent()
     {
@@ -72,11 +80,11 @@ class AutoFilter
     /**
      * Set AutoFilter Parent Worksheet.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param Worksheet $pSheet
      *
      * @return AutoFilter
      */
-    public function setParent(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet = null)
+    public function setParent(Worksheet $pSheet = null)
     {
         $this->workSheet = $pSheet;
 
@@ -98,7 +106,7 @@ class AutoFilter
      *
      * @param string $pRange Cell range (i.e. A1:E10)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter
      */
@@ -115,7 +123,7 @@ class AutoFilter
         } elseif (empty($pRange)) {
             $this->range = '';
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Autofilter must be set on a range of cells.');
+            throw new PhpSpreadsheetException('Autofilter must be set on a range of cells.');
         }
 
         if (empty($pRange)) {
@@ -123,9 +131,9 @@ class AutoFilter
             $this->columns = [];
         } else {
             //    Discard any column rules that are no longer valid within this range
-            list($rangeStart, $rangeEnd) = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($this->range);
+            list($rangeStart, $rangeEnd) = Cell::rangeBoundaries($this->range);
             foreach ($this->columns as $key => $value) {
-                $colIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($key);
+                $colIndex = Cell::columnIndexFromString($key);
                 if (($rangeStart[0] > $colIndex) || ($rangeEnd[0] < $colIndex)) {
                     unset($this->columns[$key]);
                 }
@@ -138,7 +146,7 @@ class AutoFilter
     /**
      * Get all AutoFilter Columns.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter\Column[]
      */
@@ -152,20 +160,20 @@ class AutoFilter
      *
      * @param string $column Column name (e.g. A)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return int The column offset within the autofilter range
      */
     public function testColumnInRange($column)
     {
         if (empty($this->range)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('No autofilter range is defined.');
+            throw new PhpSpreadsheetException('No autofilter range is defined.');
         }
 
-        $columnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column);
-        list($rangeStart, $rangeEnd) = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($this->range);
+        $columnIndex = Cell::columnIndexFromString($column);
+        list($rangeStart, $rangeEnd) = Cell::rangeBoundaries($this->range);
         if (($rangeStart[0] > $columnIndex) || ($rangeEnd[0] < $columnIndex)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Column is outside of current autofilter range.');
+            throw new PhpSpreadsheetException('Column is outside of current autofilter range.');
         }
 
         return $columnIndex - $rangeStart[0];
@@ -176,7 +184,7 @@ class AutoFilter
      *
      * @param string $pColumn Column name (e.g. A)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return int The offset of the specified column within the autofilter range
      */
@@ -190,7 +198,7 @@ class AutoFilter
      *
      * @param string $pColumn Column name (e.g. A)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter\Column
      */
@@ -210,14 +218,14 @@ class AutoFilter
      *
      * @param int $pColumnOffset Column offset within range (starting from 0)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter\Column
      */
     public function getColumnByOffset($pColumnOffset)
     {
-        list($rangeStart, $rangeEnd) = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($this->range);
-        $pColumn = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($rangeStart[0] + $pColumnOffset - 1);
+        list($rangeStart, $rangeEnd) = Cell::rangeBoundaries($this->range);
+        $pColumn = Cell::stringFromColumnIndex($rangeStart[0] + $pColumnOffset - 1);
 
         return $this->getColumn($pColumn);
     }
@@ -228,7 +236,7 @@ class AutoFilter
      * @param AutoFilter\Column|string $pColumn
      *            A simple string containing a Column ID like 'A' is permitted
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter
      */
@@ -239,7 +247,7 @@ class AutoFilter
         } elseif (is_object($pColumn) && ($pColumn instanceof AutoFilter\Column)) {
             $column = $pColumn->getColumnIndex();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Column is not within the autofilter range.');
+            throw new PhpSpreadsheetException('Column is not within the autofilter range.');
         }
         $this->testColumnInRange($column);
 
@@ -259,7 +267,7 @@ class AutoFilter
      *
      * @param string $pColumn Column name (e.g. A)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter
      */
@@ -340,7 +348,7 @@ class AutoFilter
         }
 
         if (is_numeric($cellValue)) {
-            $dateValue = \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($cellValue);
+            $dateValue = Date::excelToTimestamp($cellValue);
             if ($cellValue < 1) {
                 //    Just the time part
                 $dtVal = date('His', $dateValue);
@@ -460,7 +468,7 @@ class AutoFilter
         }
 
         if (is_numeric($cellValue)) {
-            $dateValue = date('m', \PhpOffice\PhpSpreadsheet\Shared\Date::excelToTimestamp($cellValue));
+            $dateValue = date('m', Date::excelToTimestamp($cellValue));
             if (in_array($dateValue, $monthSet)) {
                 return true;
             }
@@ -487,12 +495,12 @@ class AutoFilter
      */
     private function dynamicFilterDateRange($dynamicRuleType, &$filterColumn)
     {
-        $rDateType = \PhpOffice\PhpSpreadsheet\Calculation\Functions::getReturnDateType();
-        \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType(\PhpOffice\PhpSpreadsheet\Calculation\Functions::RETURNDATE_PHP_NUMERIC);
+        $rDateType = Functions::getReturnDateType();
+        Functions::setReturnDateType(Functions::RETURNDATE_PHP_NUMERIC);
         $val = $maxVal = null;
 
         $ruleValues = [];
-        $baseDate = \PhpOffice\PhpSpreadsheet\Calculation\DateTime::DATENOW();
+        $baseDate = DateTime::DATENOW();
         //    Calculate start/end dates for the required date range based on current date
         switch ($dynamicRuleType) {
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_LASTWEEK:
@@ -525,41 +533,41 @@ class AutoFilter
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_TODAY:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_YESTERDAY:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_TOMORROW:
-                $maxVal = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPtoExcel(strtotime('+1 day', $baseDate));
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($baseDate);
+                $maxVal = (int) Date::PHPtoExcel(strtotime('+1 day', $baseDate));
+                $val = (int) Date::PHPToExcel($baseDate);
                 break;
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_YEARTODATE:
-                $maxVal = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPtoExcel(strtotime('+1 day', $baseDate));
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1, date('Y', $baseDate)));
+                $maxVal = (int) Date::PHPtoExcel(strtotime('+1 day', $baseDate));
+                $val = (int) Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1, date('Y', $baseDate)));
                 break;
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_THISYEAR:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_LASTYEAR:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_NEXTYEAR:
-                $maxVal = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, 31, 12, date('Y', $baseDate)));
+                $maxVal = (int) Date::PHPToExcel(gmmktime(0, 0, 0, 31, 12, date('Y', $baseDate)));
                 ++$maxVal;
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1, date('Y', $baseDate)));
+                $val = (int) Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1, date('Y', $baseDate)));
                 break;
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_THISQUARTER:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_LASTQUARTER:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_NEXTQUARTER:
                 $thisMonth = date('m', $baseDate);
                 $thisQuarter = floor(--$thisMonth / 3);
-                $maxVal = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPtoExcel(gmmktime(0, 0, 0, date('t', $baseDate), (1 + $thisQuarter) * 3, date('Y', $baseDate)));
+                $maxVal = (int) Date::PHPtoExcel(gmmktime(0, 0, 0, date('t', $baseDate), (1 + $thisQuarter) * 3, date('Y', $baseDate)));
                 ++$maxVal;
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1 + $thisQuarter * 3, date('Y', $baseDate)));
+                $val = (int) Date::PHPToExcel(gmmktime(0, 0, 0, 1, 1 + $thisQuarter * 3, date('Y', $baseDate)));
                 break;
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_THISMONTH:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_LASTMONTH:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_NEXTMONTH:
-                $maxVal = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPtoExcel(gmmktime(0, 0, 0, date('t', $baseDate), date('m', $baseDate), date('Y', $baseDate)));
+                $maxVal = (int) Date::PHPtoExcel(gmmktime(0, 0, 0, date('t', $baseDate), date('m', $baseDate), date('Y', $baseDate)));
                 ++$maxVal;
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel(gmmktime(0, 0, 0, 1, date('m', $baseDate), date('Y', $baseDate)));
+                $val = (int) Date::PHPToExcel(gmmktime(0, 0, 0, 1, date('m', $baseDate), date('Y', $baseDate)));
                 break;
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_THISWEEK:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_LASTWEEK:
             case AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_NEXTWEEK:
                 $dayOfWeek = date('w', $baseDate);
-                $val = (int) \PhpOffice\PhpSpreadsheet\Shared\Date::PHPToExcel($baseDate) - $dayOfWeek;
+                $val = (int) Date::PHPToExcel($baseDate) - $dayOfWeek;
                 $maxVal = $val + 7;
                 break;
         }
@@ -582,7 +590,7 @@ class AutoFilter
         //    Set the rules for identifying rows for hide/show
         $ruleValues[] = ['operator' => AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_GREATERTHANOREQUAL, 'value' => $val];
         $ruleValues[] = ['operator' => AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_LESSTHAN, 'value' => $maxVal];
-        \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType($rDateType);
+        Functions::setReturnDateType($rDateType);
 
         return ['method' => 'filterTestInCustomDataSet', 'arguments' => ['filterRules' => $ruleValues, 'join' => AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND]];
     }
@@ -590,7 +598,7 @@ class AutoFilter
     private function calculateTopTenValue($columnID, $startRow, $endRow, $ruleType, $ruleValue)
     {
         $range = $columnID . $startRow . ':' . $columnID . $endRow;
-        $dataValues = \PhpOffice\PhpSpreadsheet\Calculation\Functions::flattenArray($this->workSheet->rangeToArray($range, null, true, false));
+        $dataValues = Functions::flattenArray($this->workSheet->rangeToArray($range, null, true, false));
 
         $dataValues = array_filter($dataValues);
         if ($ruleType == AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_TOPTEN_TOP) {
@@ -605,13 +613,13 @@ class AutoFilter
     /**
      * Apply the AutoFilter rules to the AutoFilter Range.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return AutoFilter
      */
     public function showHideRows()
     {
-        list($rangeStart, $rangeEnd) = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($this->range);
+        list($rangeStart, $rangeEnd) = Cell::rangeBoundaries($this->range);
 
         //    The heading row should always be visible
         $this->workSheet->getRowDimension($rangeStart[1])->setVisible(true);
@@ -721,7 +729,7 @@ class AutoFilter
                             //    Number (Average) based
                             //    Calculate the average
                             $averageFormula = '=AVERAGE(' . $columnID . ($rangeStart[1] + 1) . ':' . $columnID . $rangeEnd[1] . ')';
-                            $average = \PhpOffice\PhpSpreadsheet\Calculation::getInstance()->calculateFormula($averageFormula, null, $this->workSheet->getCell('A1'));
+                            $average = Calculation::getInstance()->calculateFormula($averageFormula, null, $this->workSheet->getCell('A1'));
                             //    Set above/below rule based on greaterThan or LessTan
                             $operator = ($dynamicRuleType === AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMIC_ABOVEAVERAGE)
                                 ? AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_GREATERTHAN
diff --git a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
index 305d70bf..11698ff8 100644
--- a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
+++ b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -68,7 +71,7 @@ class Column
     /**
      * Autofilter.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter
+     * @var AutoFilter
      */
     private $parent;
 
@@ -111,9 +114,9 @@ class Column
      * Create a new Column.
      *
      * @param string $pColumn Column (e.g. A)
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter $pParent Autofilter for this column
+     * @param AutoFilter $pParent Autofilter for this column
      */
-    public function __construct($pColumn, \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter $pParent = null)
+    public function __construct($pColumn, AutoFilter $pParent = null)
     {
         $this->columnIndex = $pColumn;
         $this->parent = $pParent;
@@ -134,7 +137,7 @@ class Column
      *
      * @param string $pColumn Column (e.g. A)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column
      */
@@ -154,7 +157,7 @@ class Column
     /**
      * Get this Column's AutoFilter Parent.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter
+     * @return AutoFilter
      */
     public function getParent()
     {
@@ -168,7 +171,7 @@ class Column
      *
      * @return Column
      */
-    public function setParent(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter $pParent = null)
+    public function setParent(AutoFilter $pParent = null)
     {
         $this->parent = $pParent;
 
@@ -190,14 +193,14 @@ class Column
      *
      * @param string $pFilterType
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column
      */
     public function setFilterType($pFilterType)
     {
         if (!in_array($pFilterType, self::$filterTypes)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid filter type for column AutoFilter.');
+            throw new PhpSpreadsheetException('Invalid filter type for column AutoFilter.');
         }
 
         $this->filterType = $pFilterType;
@@ -220,7 +223,7 @@ class Column
      *
      * @param string $pJoin And/Or
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column
      */
@@ -229,7 +232,7 @@ class Column
         // Lowercase And/Or
         $pJoin = strtolower($pJoin);
         if (!in_array($pJoin, self::$ruleJoins)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid rule connection for column AutoFilter.');
+            throw new PhpSpreadsheetException('Invalid rule connection for column AutoFilter.');
         }
 
         $this->join = $pJoin;
@@ -242,7 +245,7 @@ class Column
      *
      * @param string[] $attributes
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column
      */
@@ -259,7 +262,7 @@ class Column
      * @param string $pName Attribute Name
      * @param string $pValue Attribute Value
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column
      */
@@ -299,7 +302,7 @@ class Column
     /**
      * Get all AutoFilter Column Rules.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Column\Rule[]
      */
diff --git a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
index bdf6fd52..37f52cbf 100644
--- a/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
+++ b/src/PhpSpreadsheet/Worksheet/AutoFilter/Column/Rule.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -222,7 +225,7 @@ class Rule
     /**
      * Autofilter Column.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column
+     * @var Column
      */
     private $parent = null;
 
@@ -257,9 +260,9 @@ class Rule
     /**
      * Create a new Rule.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column $pParent
+     * @param Column $pParent
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column $pParent = null)
+    public function __construct(Column $pParent = null)
     {
         $this->parent = $pParent;
     }
@@ -279,14 +282,14 @@ class Rule
      *
      * @param string $pRuleType see self::AUTOFILTER_RULETYPE_*
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Rule
      */
     public function setRuleType($pRuleType)
     {
         if (!in_array($pRuleType, self::$ruleTypes)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid rule type for column AutoFilter Rule.');
+            throw new PhpSpreadsheetException('Invalid rule type for column AutoFilter Rule.');
         }
 
         $this->ruleType = $pRuleType;
@@ -309,7 +312,7 @@ class Rule
      *
      * @param string|string[] $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Rule
      */
@@ -328,7 +331,7 @@ class Rule
                 }
             }
             if (count($pValue) == 0) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid rule value for column AutoFilter Rule.');
+                throw new PhpSpreadsheetException('Invalid rule value for column AutoFilter Rule.');
             }
             //    Set the dateTime grouping that we've anticipated
             $this->setGrouping(self::$dateTimeGroups[$grouping]);
@@ -353,7 +356,7 @@ class Rule
      *
      * @param string $pOperator see self::AUTOFILTER_COLUMN_RULE_*
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Rule
      */
@@ -364,7 +367,7 @@ class Rule
         }
         if ((!in_array($pOperator, self::$operators)) &&
             (!in_array($pOperator, self::$topTenValue))) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid operator for column AutoFilter Rule.');
+            throw new PhpSpreadsheetException('Invalid operator for column AutoFilter Rule.');
         }
         $this->operator = $pOperator;
 
@@ -386,7 +389,7 @@ class Rule
      *
      * @param string $pGrouping
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Rule
      */
@@ -396,7 +399,7 @@ class Rule
             (!in_array($pGrouping, self::$dateTimeGroups)) &&
             (!in_array($pGrouping, self::$dynamicTypes)) &&
             (!in_array($pGrouping, self::$topTenType))) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid rule type for column AutoFilter Rule.');
+            throw new PhpSpreadsheetException('Invalid rule type for column AutoFilter Rule.');
         }
         $this->grouping = $pGrouping;
 
@@ -410,7 +413,7 @@ class Rule
      * @param string|string[] $pValue
      * @param string $pGrouping
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Rule
      */
@@ -431,7 +434,7 @@ class Rule
     /**
      * Get this Rule's AutoFilter Column Parent.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column
+     * @return Column
      */
     public function getParent()
     {
@@ -445,7 +448,7 @@ class Rule
      *
      * @return Rule
      */
-    public function setParent(\PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column $pParent = null)
+    public function setParent(Column $pParent = null)
     {
         $this->parent = $pParent;
 
diff --git a/src/PhpSpreadsheet/Worksheet/BaseDrawing.php b/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
index 9f975309..9f9ad163 100644
--- a/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
+++ b/src/PhpSpreadsheet/Worksheet/BaseDrawing.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +28,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
+class BaseDrawing implements IComparable
 {
     /**
      * Image counter.
@@ -210,14 +214,14 @@ class BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
     /**
      * Set Worksheet.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pValue
+     * @param Worksheet $pValue
      * @param bool $pOverrideOld If a Worksheet has already been assigned, overwrite it and remove image from old Worksheet?
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return BaseDrawing
      */
-    public function setWorksheet(\PhpOffice\PhpSpreadsheet\Worksheet $pValue = null, $pOverrideOld = false)
+    public function setWorksheet(Worksheet $pValue = null, $pOverrideOld = false)
     {
         if (is_null($this->worksheet)) {
             // Add drawing to \PhpOffice\PhpSpreadsheet\Worksheet
@@ -240,7 +244,7 @@ class BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
                 // Set new \PhpOffice\PhpSpreadsheet\Worksheet
                 $this->setWorksheet($pValue);
             } else {
-                throw new \PhpOffice\PhpSpreadsheet\Exception("A \PhpOffice\PhpSpreadsheet\Worksheet has already been assigned. Drawings can only exist on one \PhpOffice\PhpSpreadsheet\Worksheet.");
+                throw new PhpSpreadsheetException("A Worksheet has already been assigned. Drawings can only exist on one \PhpOffice\PhpSpreadsheet\Worksheet.");
             }
         }
 
@@ -479,7 +483,7 @@ class BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
      *
      * @param Drawing\Shadow $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return BaseDrawing
      */
diff --git a/src/PhpSpreadsheet/Worksheet/CellIterator.php b/src/PhpSpreadsheet/Worksheet/CellIterator.php
index cc3b10ea..195307f0 100644
--- a/src/PhpSpreadsheet/Worksheet/CellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/CellIterator.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -27,7 +29,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 abstract class CellIterator
 {
     /**
-     * \PhpOffice\PhpSpreadsheet\Worksheet to iterate.
+     * Worksheet to iterate.
      *
      * @var \PhpOffice\PhpSpreadsheet\Worksheet
      */
@@ -68,7 +70,7 @@ abstract class CellIterator
     /**
      * Validate start/end values for "IterateOnlyExistingCells" mode, and adjust if necessary.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     abstract protected function adjustForExistingOnlyRange();
 
@@ -77,7 +79,7 @@ abstract class CellIterator
      *
      * @param bool $value
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function setIterateOnlyExistingCells($value)
     {
diff --git a/src/PhpSpreadsheet/Worksheet/Column.php b/src/PhpSpreadsheet/Worksheet/Column.php
index d1e40750..12aa2a40 100644
--- a/src/PhpSpreadsheet/Worksheet/Column.php
+++ b/src/PhpSpreadsheet/Worksheet/Column.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -43,10 +45,10 @@ class Column
     /**
      * Create a new column.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $parent
+     * @param Worksheet $parent
      * @param string $columnIndex
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $parent = null, $columnIndex = 'A')
+    public function __construct(Worksheet $parent = null, $columnIndex = 'A')
     {
         // Set parent and column index
         $this->parent = $parent;
diff --git a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
index 8fcef2fb..1538b825 100644
--- a/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/ColumnCellIterator.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -50,16 +54,16 @@ class ColumnCellIterator extends CellIterator implements \Iterator
     /**
      * Create a new row iterator.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $subject The worksheet to iterate over
+     * @param Worksheet $subject The worksheet to iterate over
      * @param string $columnIndex The column that we want to iterate
      * @param int $startRow The row number at which to start iterating
      * @param int $endRow Optionally, the row number at which to stop iterating
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $subject = null, $columnIndex = 'A', $startRow = 1, $endRow = null)
+    public function __construct(Worksheet $subject = null, $columnIndex = 'A', $startRow = 1, $endRow = null)
     {
         // Set subject
         $this->subject = $subject;
-        $this->columnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnIndex) - 1;
+        $this->columnIndex = Cell::columnIndexFromString($columnIndex) - 1;
         $this->resetEnd($endRow);
         $this->resetStart($startRow);
     }
@@ -77,7 +81,7 @@ class ColumnCellIterator extends CellIterator implements \Iterator
      *
      * @param int $startRow The row number at which to start iterating
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return ColumnCellIterator
      */
@@ -95,7 +99,7 @@ class ColumnCellIterator extends CellIterator implements \Iterator
      *
      * @param int $endRow The row number at which to stop iterating
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return ColumnCellIterator
      */
@@ -112,16 +116,16 @@ class ColumnCellIterator extends CellIterator implements \Iterator
      *
      * @param int $row The row number to set the current pointer at
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return ColumnCellIterator
      */
     public function seek($row = 1)
     {
         if (($row < $this->startRow) || ($row > $this->endRow)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Row $row is out of range ({$this->startRow} - {$this->endRow})");
+            throw new PhpSpreadsheetException("Row $row is out of range ({$this->startRow} - {$this->endRow})");
         } elseif ($this->onlyExistingCells && !($this->subject->cellExistsByColumnAndRow($this->columnIndex, $row))) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('In "IterateOnlyExistingCells" mode and Cell does not exist');
+            throw new PhpSpreadsheetException('In "IterateOnlyExistingCells" mode and Cell does not exist');
         }
         $this->position = $row;
 
@@ -139,7 +143,7 @@ class ColumnCellIterator extends CellIterator implements \Iterator
     /**
      * Return the current cell in this worksheet column.
      *
-     * @return null|\PhpOffice\PhpSpreadsheet\Cell
+     * @return null|Cell
      */
     public function current()
     {
@@ -174,7 +178,7 @@ class ColumnCellIterator extends CellIterator implements \Iterator
     public function prev()
     {
         if ($this->position <= $this->startRow) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
+            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
         }
 
         do {
@@ -197,7 +201,7 @@ class ColumnCellIterator extends CellIterator implements \Iterator
     /**
      * Validate start/end values for "IterateOnlyExistingCells" mode, and adjust if necessary.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     protected function adjustForExistingOnlyRange()
     {
@@ -207,14 +211,14 @@ class ColumnCellIterator extends CellIterator implements \Iterator
                 ++$this->startRow;
             }
             if ($this->startRow > $this->endRow) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('No cells exist within the specified range');
+                throw new PhpSpreadsheetException('No cells exist within the specified range');
             }
             while ((!$this->subject->cellExistsByColumnAndRow($this->columnIndex, $this->endRow)) &&
                 ($this->endRow >= $this->startRow)) {
                 --$this->endRow;
             }
             if ($this->endRow < $this->startRow) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('No cells exist within the specified range');
+                throw new PhpSpreadsheetException('No cells exist within the specified range');
             }
         }
     }
diff --git a/src/PhpSpreadsheet/Worksheet/ColumnIterator.php b/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
index 9dfc6db9..77e931cb 100644
--- a/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/ColumnIterator.php
@@ -4,23 +4,22 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
 use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Exception;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
- *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
- *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
- *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * @category   PhpSpreadsheet
  *
@@ -30,7 +29,7 @@ use PhpOffice\PhpSpreadsheet\Exception;
 class ColumnIterator implements \Iterator
 {
     /**
-     * \PhpOffice\PhpSpreadsheet\Worksheet to iterate.
+     * Worksheet to iterate.
      *
      * @var \PhpOffice\PhpSpreadsheet\Worksheet
      */
@@ -60,11 +59,11 @@ class ColumnIterator implements \Iterator
     /**
      * Create a new column iterator.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $subject The worksheet to iterate over
+     * @param Worksheet $subject The worksheet to iterate over
      * @param string $startColumn The column address at which to start iterating
      * @param string $endColumn Optionally, the column address at which to stop iterating
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $subject, $startColumn = 'A', $endColumn = null)
+    public function __construct(Worksheet $subject, $startColumn = 'A', $endColumn = null)
     {
         // Set subject
         $this->subject = $subject;
@@ -91,7 +90,7 @@ class ColumnIterator implements \Iterator
      */
     public function resetStart($startColumn = 'A')
     {
-        $startColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($startColumn) - 1;
+        $startColumnIndex = Cell::columnIndexFromString($startColumn) - 1;
         if ($startColumnIndex > Cell::columnIndexFromString($this->subject->getHighestColumn()) - 1) {
             throw new Exception("Start column ({$startColumn}) is beyond highest column ({$this->subject->getHighestColumn()})");
         }
@@ -115,7 +114,7 @@ class ColumnIterator implements \Iterator
     public function resetEnd($endColumn = null)
     {
         $endColumn = ($endColumn) ? $endColumn : $this->subject->getHighestColumn();
-        $this->endColumn = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($endColumn) - 1;
+        $this->endColumn = Cell::columnIndexFromString($endColumn) - 1;
 
         return $this;
     }
@@ -125,15 +124,15 @@ class ColumnIterator implements \Iterator
      *
      * @param string $column The column address to set the current pointer at
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return ColumnIterator
      */
     public function seek($column = 'A')
     {
-        $column = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+        $column = Cell::columnIndexFromString($column) - 1;
         if (($column < $this->startColumn) || ($column > $this->endColumn)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Column $column is out of range ({$this->startColumn} - {$this->endColumn})");
+            throw new PhpSpreadsheetException("Column $column is out of range ({$this->startColumn} - {$this->endColumn})");
         }
         $this->position = $column;
 
@@ -155,7 +154,7 @@ class ColumnIterator implements \Iterator
      */
     public function current()
     {
-        return new Column($this->subject, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->position));
+        return new Column($this->subject, Cell::stringFromColumnIndex($this->position));
     }
 
     /**
@@ -165,7 +164,7 @@ class ColumnIterator implements \Iterator
      */
     public function key()
     {
-        return \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->position);
+        return Cell::stringFromColumnIndex($this->position);
     }
 
     /**
@@ -179,18 +178,13 @@ class ColumnIterator implements \Iterator
     /**
      * Set the iterator to its previous value.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function prev()
     {
         if ($this->position <= $this->startColumn) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception(
-                'Column is already at the beginning of range (' .
-                \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->endColumn) . ' - ' .
-                \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->endColumn) . ')'
-            );
+            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Cell::stringFromColumnIndex($this->endColumn) . ' - ' . Cell::stringFromColumnIndex($this->endColumn) . ')');
         }
-
         --$this->position;
     }
 
diff --git a/src/PhpSpreadsheet/Worksheet/Dimension.php b/src/PhpSpreadsheet/Worksheet/Dimension.php
index 2ff18512..0f172d36 100644
--- a/src/PhpSpreadsheet/Worksheet/Dimension.php
+++ b/src/PhpSpreadsheet/Worksheet/Dimension.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -101,19 +103,18 @@ abstract class Dimension
 
     /**
      * Set Outline Level.
-     *
-     * Value must be between 0 and 7
+     * Value must be between 0 and 7.
      *
      * @param int $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Dimension
      */
     public function setOutlineLevel($pValue)
     {
         if ($pValue < 0 || $pValue > 7) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Outline level must range between 0 and 7.');
+            throw new PhpSpreadsheetException('Outline level must range between 0 and 7.');
         }
 
         $this->outlineLevel = $pValue;
diff --git a/src/PhpSpreadsheet/Worksheet/Drawing.php b/src/PhpSpreadsheet/Worksheet/Drawing.php
index 8154e501..3341ac9d 100644
--- a/src/PhpSpreadsheet/Worksheet/Drawing.php
+++ b/src/PhpSpreadsheet/Worksheet/Drawing.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Drawing extends BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
+class Drawing extends BaseDrawing implements IComparable
 {
     /**
      * Path.
@@ -96,7 +99,7 @@ class Drawing extends BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparab
      * @param string $pValue File path
      * @param bool $pVerifyFile Verify file
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Drawing
      */
@@ -111,7 +114,7 @@ class Drawing extends BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparab
                     list($this->width, $this->height) = getimagesize($pValue);
                 }
             } else {
-                throw new \PhpOffice\PhpSpreadsheet\Exception("File $pValue not found!");
+                throw new PhpSpreadsheetException("File $pValue not found!");
             }
         } else {
             $this->path = $pValue;
diff --git a/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php b/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
index 54f23a83..22a70289 100644
--- a/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
+++ b/src/PhpSpreadsheet/Worksheet/Drawing/Shadow.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +28,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Shadow implements \PhpOffice\PhpSpreadsheet\IComparable
+class Shadow implements IComparable
 {
     /* Shadow alignment */
     const SHADOW_BOTTOM = 'b';
@@ -78,7 +82,7 @@ class Shadow implements \PhpOffice\PhpSpreadsheet\IComparable
     /**
      * Color.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Style\Color
+     * @var Color
      */
     private $color;
 
@@ -100,7 +104,7 @@ class Shadow implements \PhpOffice\PhpSpreadsheet\IComparable
         $this->distance = 2;
         $this->direction = 0;
         $this->alignment = self::SHADOW_BOTTOM_RIGHT;
-        $this->color = new \PhpOffice\PhpSpreadsheet\Style\Color(\PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK);
+        $this->color = new Color(Color::COLOR_BLACK);
         $this->alpha = 50;
     }
 
@@ -227,7 +231,7 @@ class Shadow implements \PhpOffice\PhpSpreadsheet\IComparable
     /**
      * Get Color.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Color
+     * @return Color
      */
     public function getColor()
     {
@@ -237,13 +241,13 @@ class Shadow implements \PhpOffice\PhpSpreadsheet\IComparable
     /**
      * Set Color.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Color $pValue
+     * @param Color $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return Shadow
      */
-    public function setColor(\PhpOffice\PhpSpreadsheet\Style\Color $pValue = null)
+    public function setColor(Color $pValue = null)
     {
         $this->color = $pValue;
 
diff --git a/src/PhpSpreadsheet/Worksheet/HeaderFooter.php b/src/PhpSpreadsheet/Worksheet/HeaderFooter.php
index 92760132..4b58ac49 100644
--- a/src/PhpSpreadsheet/Worksheet/HeaderFooter.php
+++ b/src/PhpSpreadsheet/Worksheet/HeaderFooter.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -424,7 +426,7 @@ class HeaderFooter
      * @param HeaderFooterDrawing $image
      * @param string $location
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return HeaderFooter
      */
@@ -440,7 +442,7 @@ class HeaderFooter
      *
      * @param string $location
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return HeaderFooter
      */
@@ -458,7 +460,7 @@ class HeaderFooter
      *
      * @param HeaderFooterDrawing[] $images
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return HeaderFooter
      */
diff --git a/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php b/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
index 6db76ff5..274339dd 100644
--- a/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
+++ b/src/PhpSpreadsheet/Worksheet/HeaderFooterDrawing.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class HeaderFooterDrawing extends Drawing implements \PhpOffice\PhpSpreadsheet\IComparable
+class HeaderFooterDrawing extends Drawing implements IComparable
 {
     /**
      * Path.
@@ -318,7 +321,7 @@ class HeaderFooterDrawing extends Drawing implements \PhpOffice\PhpSpreadsheet\I
      * @param string $pValue File path
      * @param bool $pVerifyFile Verify file
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return HeaderFooterDrawing
      */
@@ -333,7 +336,7 @@ class HeaderFooterDrawing extends Drawing implements \PhpOffice\PhpSpreadsheet\I
                     list($this->width, $this->height) = getimagesize($pValue);
                 }
             } else {
-                throw new \PhpOffice\PhpSpreadsheet\Exception("File $pValue not found!");
+                throw new PhpSpreadsheetException("File $pValue not found!");
             }
         } else {
             $this->path = $pValue;
diff --git a/src/PhpSpreadsheet/Worksheet/Iterator.php b/src/PhpSpreadsheet/Worksheet/Iterator.php
index c7cdbc19..d7406aec 100644
--- a/src/PhpSpreadsheet/Worksheet/Iterator.php
+++ b/src/PhpSpreadsheet/Worksheet/Iterator.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,7 +31,7 @@ class Iterator implements \Iterator
     /**
      * Spreadsheet to iterate.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $subject;
 
@@ -43,9 +45,9 @@ class Iterator implements \Iterator
     /**
      * Create a new worksheet iterator.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $subject
+     * @param Spreadsheet $subject
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $subject = null)
+    public function __construct(Spreadsheet $subject = null)
     {
         // Set subject
         $this->subject = $subject;
diff --git a/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php b/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
index b543b8d0..f085d0e1 100644
--- a/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
+++ b/src/PhpSpreadsheet/Worksheet/MemoryDrawing.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\IComparable;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -24,7 +26,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class MemoryDrawing extends BaseDrawing implements \PhpOffice\PhpSpreadsheet\IComparable
+class MemoryDrawing extends BaseDrawing implements IComparable
 {
     /* Rendering functions */
     const RENDERING_DEFAULT = 'imagepng';
diff --git a/src/PhpSpreadsheet/Worksheet/PageSetup.php b/src/PhpSpreadsheet/Worksheet/PageSetup.php
index 8e40ca1d..f001ecaf 100644
--- a/src/PhpSpreadsheet/Worksheet/PageSetup.php
+++ b/src/PhpSpreadsheet/Worksheet/PageSetup.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -335,14 +338,13 @@ class PageSetup
 
     /**
      * Set Scale.
-     *
      * Print scaling. Valid values range from 10 to 400
-     * This setting is overridden when fitToWidth and/or fitToHeight are in use
+     * This setting is overridden when fitToWidth and/or fitToHeight are in use.
      *
      * @param int|null $pValue
      * @param bool $pUpdate Update fitToPage so scaling applies rather than fitToHeight / fitToWidth
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return PageSetup
      */
@@ -356,7 +358,7 @@ class PageSetup
                 $this->fitToPage = false;
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Scale must not be negative');
+            throw new PhpSpreadsheetException('Scale must not be negative');
         }
 
         return $this;
@@ -608,7 +610,7 @@ class PageSetup
      *                            Otherwise, the specific range identified by the value of $index will be returned
      *                            Print areas are numbered from 1
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return string
      */
@@ -621,7 +623,7 @@ class PageSetup
         if (isset($printAreas[$index - 1])) {
             return $printAreas[$index - 1];
         }
-        throw new \PhpOffice\PhpSpreadsheet\Exception('Requested Print Area does not exist');
+        throw new PhpSpreadsheetException('Requested Print Area does not exist');
     }
 
     /**
@@ -687,18 +689,18 @@ class PageSetup
      *                            Default behaviour, or the "O" method, overwrites existing print area
      *                            The "I" method, inserts the new print area before any specified index, or at the end of the list
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return PageSetup
      */
     public function setPrintArea($value, $index = 0, $method = self::SETPRINTRANGE_OVERWRITE)
     {
         if (strpos($value, '!') !== false) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Cell coordinate must not specify a worksheet.');
+            throw new PhpSpreadsheetException('Cell coordinate must not specify a worksheet.');
         } elseif (strpos($value, ':') === false) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Cell coordinate must be a range of cells.');
+            throw new PhpSpreadsheetException('Cell coordinate must be a range of cells.');
         } elseif (strpos($value, '$') !== false) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Cell coordinate must not be absolute.');
+            throw new PhpSpreadsheetException('Cell coordinate must not be absolute.');
         }
         $value = strtoupper($value);
 
@@ -711,7 +713,7 @@ class PageSetup
                     $index = count($printAreas) - abs($index) + 1;
                 }
                 if (($index <= 0) || ($index > count($printAreas))) {
-                    throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid index for setting print range.');
+                    throw new PhpSpreadsheetException('Invalid index for setting print range.');
                 }
                 $printAreas[$index - 1] = $value;
                 $this->printArea = implode(',', $printAreas);
@@ -725,13 +727,13 @@ class PageSetup
                     $index = abs($index) - 1;
                 }
                 if ($index > count($printAreas)) {
-                    throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid index for setting print range.');
+                    throw new PhpSpreadsheetException('Invalid index for setting print range.');
                 }
                 $printAreas = array_merge(array_slice($printAreas, 0, $index), [$value], array_slice($printAreas, $index));
                 $this->printArea = implode(',', $printAreas);
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid method for setting print range.');
+            throw new PhpSpreadsheetException('Invalid method for setting print range.');
         }
 
         return $this;
@@ -748,7 +750,7 @@ class PageSetup
      *                                list.
      *                            Print areas are numbered from 1
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return PageSetup
      */
@@ -778,14 +780,14 @@ class PageSetup
      *                                Default behaviour, or the "O" method, overwrites existing print area
      *                                The "I" method, inserts the new print area before any specified index, or at the end of the list
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return PageSetup
      */
     public function setPrintAreaByColumnAndRow($column1, $row1, $column2, $row2, $index = 0, $method = self::SETPRINTRANGE_OVERWRITE)
     {
         return $this->setPrintArea(
-            \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column1) . $row1 . ':' . \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column2) . $row2,
+            Cell::stringFromColumnIndex($column1) . $row1 . ':' . Cell::stringFromColumnIndex($column2) . $row2,
             $index,
             $method
         );
@@ -805,14 +807,14 @@ class PageSetup
      *                                    list.
      *                                Print areas are numbered from 1
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return PageSetup
      */
     public function addPrintAreaByColumnAndRow($column1, $row1, $column2, $row2, $index = -1)
     {
         return $this->setPrintArea(
-            \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column1) . $row1 . ':' . \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column2) . $row2,
+            Cell::stringFromColumnIndex($column1) . $row1 . ':' . Cell::stringFromColumnIndex($column2) . $row2,
             $index,
             self::SETPRINTRANGE_INSERT
         );
diff --git a/src/PhpSpreadsheet/Worksheet/Protection.php b/src/PhpSpreadsheet/Worksheet/Protection.php
index ddb2dac3..ef96ba58 100644
--- a/src/PhpSpreadsheet/Worksheet/Protection.php
+++ b/src/PhpSpreadsheet/Worksheet/Protection.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Shared\PasswordHasher;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -582,7 +584,7 @@ class Protection
     public function setPassword($pValue, $pAlreadyHashed = false)
     {
         if (!$pAlreadyHashed) {
-            $pValue = \PhpOffice\PhpSpreadsheet\Shared\PasswordHasher::hashPassword($pValue);
+            $pValue = PasswordHasher::hashPassword($pValue);
         }
         $this->password = $pValue;
 
diff --git a/src/PhpSpreadsheet/Worksheet/Row.php b/src/PhpSpreadsheet/Worksheet/Row.php
index 5e565980..7a438e6f 100644
--- a/src/PhpSpreadsheet/Worksheet/Row.php
+++ b/src/PhpSpreadsheet/Worksheet/Row.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -43,10 +45,10 @@ class Row
     /**
      * Create a new row.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $parent
+     * @param Worksheet $parent
      * @param int $rowIndex
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $worksheet = null, $rowIndex = 1)
+    public function __construct(Worksheet $worksheet = null, $rowIndex = 1)
     {
         // Set parent and row index
         $this->worksheet = $worksheet;
diff --git a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
index 8ae0eb63..de111d42 100644
--- a/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowCellIterator.php
@@ -2,22 +2,23 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
- *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
- *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * Lesser General Public License for more details.
- *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * @category   PhpSpreadsheet
  *
@@ -50,12 +51,12 @@ class RowCellIterator extends CellIterator implements \Iterator
     /**
      * Create a new column iterator.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $subject The worksheet to iterate over
+     * @param Worksheet $subject The worksheet to iterate over
      * @param int $rowIndex The row that we want to iterate
      * @param string $startColumn The column address at which to start iterating
      * @param string $endColumn Optionally, the column address at which to stop iterating
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $subject = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null)
+    public function __construct(Worksheet $subject = null, $rowIndex = 1, $startColumn = 'A', $endColumn = null)
     {
         // Set subject and row index
         $this->subject = $subject;
@@ -77,16 +78,16 @@ class RowCellIterator extends CellIterator implements \Iterator
      *
      * @param int $startColumn The column address at which to start iterating
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return RowCellIterator
      */
     public function resetStart($startColumn = 'A')
     {
-        $startColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($startColumn) - 1;
+        $startColumnIndex = Cell::columnIndexFromString($startColumn) - 1;
         $this->startColumn = $startColumnIndex;
         $this->adjustForExistingOnlyRange();
-        $this->seek(\PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->startColumn));
+        $this->seek(Cell::stringFromColumnIndex($this->startColumn));
 
         return $this;
     }
@@ -96,14 +97,14 @@ class RowCellIterator extends CellIterator implements \Iterator
      *
      * @param string $endColumn The column address at which to stop iterating
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return RowCellIterator
      */
     public function resetEnd($endColumn = null)
     {
         $endColumn = ($endColumn) ? $endColumn : $this->subject->getHighestColumn();
-        $this->endColumn = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($endColumn) - 1;
+        $this->endColumn = Cell::columnIndexFromString($endColumn) - 1;
         $this->adjustForExistingOnlyRange();
 
         return $this;
@@ -114,17 +115,17 @@ class RowCellIterator extends CellIterator implements \Iterator
      *
      * @param string $column The column address to set the current pointer at
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return RowCellIterator
      */
     public function seek($column = 'A')
     {
-        $column = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+        $column = Cell::columnIndexFromString($column) - 1;
         if (($column < $this->startColumn) || ($column > $this->endColumn)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Column $column is out of range ({$this->startColumn} - {$this->endColumn})");
+            throw new PhpSpreadsheetException("Column $column is out of range ({$this->startColumn} - {$this->endColumn})");
         } elseif ($this->onlyExistingCells && !($this->subject->cellExistsByColumnAndRow($column, $this->rowIndex))) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('In "IterateOnlyExistingCells" mode and Cell does not exist');
+            throw new PhpSpreadsheetException('In "IterateOnlyExistingCells" mode and Cell does not exist');
         }
         $this->position = $column;
 
@@ -142,7 +143,7 @@ class RowCellIterator extends CellIterator implements \Iterator
     /**
      * Return the current cell in this worksheet row.
      *
-     * @return \PhpOffice\PhpSpreadsheet\Cell
+     * @return Cell
      */
     public function current()
     {
@@ -156,7 +157,7 @@ class RowCellIterator extends CellIterator implements \Iterator
      */
     public function key()
     {
-        return \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->position);
+        return Cell::stringFromColumnIndex($this->position);
     }
 
     /**
@@ -166,31 +167,22 @@ class RowCellIterator extends CellIterator implements \Iterator
     {
         do {
             ++$this->position;
-        } while (($this->onlyExistingCells) &&
-            (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) &&
-            ($this->position <= $this->endColumn));
+        } while (($this->onlyExistingCells) && (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) && ($this->position <= $this->endColumn));
     }
 
     /**
      * Set the iterator to its previous value.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function prev()
     {
         if ($this->position <= $this->startColumn) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception(
-                'Column is already at the beginning of range (' .
-                \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->endColumn) . ' - ' .
-                \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($this->endColumn) . ')'
-            );
+            throw new PhpSpreadsheetException('Column is already at the beginning of range (' . Cell::stringFromColumnIndex($this->endColumn) . ' - ' . Cell::stringFromColumnIndex($this->endColumn) . ')');
         }
-
         do {
             --$this->position;
-        } while (($this->onlyExistingCells) &&
-            (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) &&
-            ($this->position >= $this->startColumn));
+        } while (($this->onlyExistingCells) && (!$this->subject->cellExistsByColumnAndRow($this->position, $this->rowIndex)) && ($this->position >= $this->startColumn));
     }
 
     /**
@@ -206,24 +198,22 @@ class RowCellIterator extends CellIterator implements \Iterator
     /**
      * Validate start/end values for "IterateOnlyExistingCells" mode, and adjust if necessary.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     protected function adjustForExistingOnlyRange()
     {
         if ($this->onlyExistingCells) {
-            while ((!$this->subject->cellExistsByColumnAndRow($this->startColumn, $this->rowIndex)) &&
-                ($this->startColumn <= $this->endColumn)) {
+            while ((!$this->subject->cellExistsByColumnAndRow($this->startColumn, $this->rowIndex)) && ($this->startColumn <= $this->endColumn)) {
                 ++$this->startColumn;
             }
             if ($this->startColumn > $this->endColumn) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('No cells exist within the specified range');
+                throw new PhpSpreadsheetException('No cells exist within the specified range');
             }
-            while ((!$this->subject->cellExistsByColumnAndRow($this->endColumn, $this->rowIndex)) &&
-                ($this->endColumn >= $this->startColumn)) {
+            while ((!$this->subject->cellExistsByColumnAndRow($this->endColumn, $this->rowIndex)) && ($this->endColumn >= $this->startColumn)) {
                 --$this->endColumn;
             }
             if ($this->endColumn < $this->startColumn) {
-                throw new \PhpOffice\PhpSpreadsheet\Exception('No cells exist within the specified range');
+                throw new PhpSpreadsheetException('No cells exist within the specified range');
             }
         }
     }
diff --git a/src/PhpSpreadsheet/Worksheet/RowIterator.php b/src/PhpSpreadsheet/Worksheet/RowIterator.php
index b92f8c9e..2aa63329 100644
--- a/src/PhpSpreadsheet/Worksheet/RowIterator.php
+++ b/src/PhpSpreadsheet/Worksheet/RowIterator.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -27,7 +30,7 @@ namespace PhpOffice\PhpSpreadsheet\Worksheet;
 class RowIterator implements \Iterator
 {
     /**
-     * \PhpOffice\PhpSpreadsheet\Worksheet to iterate.
+     * Worksheet to iterate.
      *
      * @var \PhpOffice\PhpSpreadsheet\Worksheet
      */
@@ -57,11 +60,11 @@ class RowIterator implements \Iterator
     /**
      * Create a new row iterator.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $subject The worksheet to iterate over
+     * @param Worksheet $subject The worksheet to iterate over
      * @param int $startRow The row number at which to start iterating
      * @param int $endRow Optionally, the row number at which to stop iterating
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Worksheet $subject, $startRow = 1, $endRow = null)
+    public function __construct(Worksheet $subject, $startRow = 1, $endRow = null)
     {
         // Set subject
         $this->subject = $subject;
@@ -82,14 +85,14 @@ class RowIterator implements \Iterator
      *
      * @param int $startRow The row number at which to start iterating
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return RowIterator
      */
     public function resetStart($startRow = 1)
     {
         if ($startRow > $this->subject->getHighestRow()) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Start row ({$startRow}) is beyond highest row ({$this->subject->getHighestRow()})");
+            throw new PhpSpreadsheetException("Start row ({$startRow}) is beyond highest row ({$this->subject->getHighestRow()})");
         }
 
         $this->startRow = $startRow;
@@ -120,14 +123,14 @@ class RowIterator implements \Iterator
      *
      * @param int $row The row number to set the current pointer at
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return RowIterator
      */
     public function seek($row = 1)
     {
         if (($row < $this->startRow) || ($row > $this->endRow)) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Row $row is out of range ({$this->startRow} - {$this->endRow})");
+            throw new PhpSpreadsheetException("Row $row is out of range ({$this->startRow} - {$this->endRow})");
         }
         $this->position = $row;
 
@@ -173,12 +176,12 @@ class RowIterator implements \Iterator
     /**
      * Set the iterator to its previous value.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function prev()
     {
         if ($this->position <= $this->startRow) {
-            throw new \PhpOffice\PhpSpreadsheet\Exception("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
+            throw new PhpSpreadsheetException("Row is already at the beginning of range ({$this->startRow} - {$this->endRow})");
         }
 
         --$this->position;
diff --git a/src/PhpSpreadsheet/Worksheet/SheetView.php b/src/PhpSpreadsheet/Worksheet/SheetView.php
index 7ce233ce..0966cbc3 100644
--- a/src/PhpSpreadsheet/Worksheet/SheetView.php
+++ b/src/PhpSpreadsheet/Worksheet/SheetView.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Worksheet;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -83,12 +85,11 @@ class SheetView
 
     /**
      * Set ZoomScale.
-     *
      * Valid values range from 10 to 400.
      *
      * @param int $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return SheetView
      */
@@ -99,7 +100,7 @@ class SheetView
         if (($pValue >= 1) || is_null($pValue)) {
             $this->zoomScale = $pValue;
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Scale must be greater than or equal to 1.');
+            throw new PhpSpreadsheetException('Scale must be greater than or equal to 1.');
         }
 
         return $this;
@@ -117,12 +118,11 @@ class SheetView
 
     /**
      * Set ZoomScale.
-     *
      * Valid values range from 10 to 400.
      *
      * @param int $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return SheetView
      */
@@ -131,7 +131,7 @@ class SheetView
         if (($pValue >= 1) || is_null($pValue)) {
             $this->zoomScaleNormal = $pValue;
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Scale must be greater than or equal to 1.');
+            throw new PhpSpreadsheetException('Scale must be greater than or equal to 1.');
         }
 
         return $this;
@@ -157,7 +157,7 @@ class SheetView
      *
      * @param string $pValue
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      *
      * @return SheetView
      */
@@ -170,7 +170,7 @@ class SheetView
         if (in_array($pValue, self::$sheetViewTypes)) {
             $this->sheetviewType = $pValue;
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Exception('Invalid sheetview layout type.');
+            throw new PhpSpreadsheetException('Invalid sheetview layout type.');
         }
 
         return $this;
diff --git a/src/PhpSpreadsheet/Writer/Csv.php b/src/PhpSpreadsheet/Writer/Csv.php
index 4ed6f89d..4dfb498a 100644
--- a/src/PhpSpreadsheet/Writer/Csv.php
+++ b/src/PhpSpreadsheet/Writer/Csv.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -86,9 +89,9 @@ class Csv extends BaseWriter implements IWriter
     /**
      * Create a new CSV.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet Spreadsheet object
+     * @param Spreadsheet $spreadsheet Spreadsheet object
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function __construct(Spreadsheet $spreadsheet)
     {
         $this->spreadsheet = $spreadsheet;
     }
@@ -105,10 +108,10 @@ class Csv extends BaseWriter implements IWriter
         // Fetch sheet
         $sheet = $this->spreadsheet->getSheet($this->sheetIndex);
 
-        $saveDebugLog = \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->getWriteDebugLog();
-        \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog(false);
-        $saveArrayReturnType = \PhpOffice\PhpSpreadsheet\Calculation::getArrayReturnType();
-        \PhpOffice\PhpSpreadsheet\Calculation::setArrayReturnType(\PhpOffice\PhpSpreadsheet\Calculation::RETURN_ARRAY_AS_VALUE);
+        $saveDebugLog = Calculation::getInstance($this->spreadsheet)->getDebugLog()->getWriteDebugLog();
+        Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog(false);
+        $saveArrayReturnType = Calculation::getArrayReturnType();
+        Calculation::setArrayReturnType(Calculation::RETURN_ARRAY_AS_VALUE);
 
         // Open file
         $fileHandle = fopen($pFilename, 'wb+');
@@ -147,8 +150,8 @@ class Csv extends BaseWriter implements IWriter
         // Close file
         fclose($fileHandle);
 
-        \PhpOffice\PhpSpreadsheet\Calculation::setArrayReturnType($saveArrayReturnType);
-        \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
+        Calculation::setArrayReturnType($saveArrayReturnType);
+        Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
     }
 
     /**
diff --git a/src/PhpSpreadsheet/Writer/Exception.php b/src/PhpSpreadsheet/Writer/Exception.php
index b0f4d618..5c0a8023 100644
--- a/src/PhpSpreadsheet/Writer/Exception.php
+++ b/src/PhpSpreadsheet/Writer/Exception.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -24,7 +26,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer;
  * @copyright  Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class Exception extends \PhpOffice\PhpSpreadsheet\Exception
+class Exception extends PhpSpreadsheetException
 {
     /**
      * Error handler callback.
diff --git a/src/PhpSpreadsheet/Writer/Html.php b/src/PhpSpreadsheet/Writer/Html.php
index f87812c7..0a08bc0b 100644
--- a/src/PhpSpreadsheet/Writer/Html.php
+++ b/src/PhpSpreadsheet/Writer/Html.php
@@ -3,9 +3,25 @@
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
 use PhpOffice\PhpSpreadsheet\Calculation;
-use PhpOffice\PhpSpreadsheet\Shared\Font;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Chart;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\Drawing as SharedDrawing;
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Shared\Font as SharedFont;
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Borders;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
 /**
  * Copyright (c) 2006 - 2015 Spreadsheet.
@@ -83,7 +99,7 @@ class Html extends BaseWriter implements IWriter
     /**
      * Default font.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Style\Font
+     * @var Font
      */
     private $defaultFont;
 
@@ -132,7 +148,7 @@ class Html extends BaseWriter implements IWriter
     /**
      * Create a new HTML.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      */
     public function __construct(Spreadsheet $spreadsheet)
     {
@@ -145,7 +161,7 @@ class Html extends BaseWriter implements IWriter
      *
      * @param string $pFilename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     public function save($pFilename)
     {
@@ -163,7 +179,7 @@ class Html extends BaseWriter implements IWriter
         // Open file
         $fileHandle = fopen($pFilename, 'wb+');
         if ($fileHandle === false) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not open file $pFilename for writing.");
+            throw new WriterException("Could not open file $pFilename for writing.");
         }
 
         // Write headers
@@ -197,12 +213,12 @@ class Html extends BaseWriter implements IWriter
     private function mapVAlign($vAlign)
     {
         switch ($vAlign) {
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM:
+            case Alignment::VERTICAL_BOTTOM:
                 return 'bottom';
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP:
+            case Alignment::VERTICAL_TOP:
                 return 'top';
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER:
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY:
+            case Alignment::VERTICAL_CENTER:
+            case Alignment::VERTICAL_JUSTIFY:
                 return 'middle';
             default:
                 return 'baseline';
@@ -219,16 +235,16 @@ class Html extends BaseWriter implements IWriter
     private function mapHAlign($hAlign)
     {
         switch ($hAlign) {
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL:
+            case Alignment::HORIZONTAL_GENERAL:
                 return false;
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT:
+            case Alignment::HORIZONTAL_LEFT:
                 return 'left';
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT:
+            case Alignment::HORIZONTAL_RIGHT:
                 return 'right';
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER:
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS:
+            case Alignment::HORIZONTAL_CENTER:
+            case Alignment::HORIZONTAL_CENTER_CONTINUOUS:
                 return 'center';
-            case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY:
+            case Alignment::HORIZONTAL_JUSTIFY:
                 return 'justify';
             default:
                 return false;
@@ -245,33 +261,33 @@ class Html extends BaseWriter implements IWriter
     private function mapBorderStyle($borderStyle)
     {
         switch ($borderStyle) {
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+            case Border::BORDER_NONE:
                 return 'none';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+            case Border::BORDER_DASHDOT:
                 return '1px dashed';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+            case Border::BORDER_DASHDOTDOT:
                 return '1px dotted';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+            case Border::BORDER_DASHED:
                 return '1px dashed';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+            case Border::BORDER_DOTTED:
                 return '1px dotted';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+            case Border::BORDER_DOUBLE:
                 return '3px double';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+            case Border::BORDER_HAIR:
                 return '1px solid';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+            case Border::BORDER_MEDIUM:
                 return '2px solid';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+            case Border::BORDER_MEDIUMDASHDOT:
                 return '2px dashed';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+            case Border::BORDER_MEDIUMDASHDOTDOT:
                 return '2px dotted';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+            case Border::BORDER_MEDIUMDASHED:
                 return '2px dashed';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+            case Border::BORDER_SLANTDASHDOT:
                 return '2px dashed';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+            case Border::BORDER_THICK:
                 return '3px solid';
-            case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+            case Border::BORDER_THIN:
                 return '1px solid';
             default:
                 // map others to thin
@@ -342,7 +358,7 @@ class Html extends BaseWriter implements IWriter
      *
      * @param bool $pIncludeStyles Include styles?
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
@@ -350,7 +366,7 @@ class Html extends BaseWriter implements IWriter
     {
         // Spreadsheet object known?
         if (is_null($this->spreadsheet)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Internal Spreadsheet object not set to an instance of an object.');
+            throw new WriterException('Internal Spreadsheet object not set to an instance of an object.');
         }
 
         // Construct HTML
@@ -402,7 +418,7 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate sheet data.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
@@ -410,7 +426,7 @@ class Html extends BaseWriter implements IWriter
     {
         // Spreadsheet object known?
         if (is_null($this->spreadsheet)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Internal Spreadsheet object not set to an instance of an object.');
+            throw new WriterException('Internal Spreadsheet object not set to an instance of an object.');
         }
 
         // Ensure that Spans have been calculated?
@@ -437,10 +453,10 @@ class Html extends BaseWriter implements IWriter
 
             // Get worksheet dimension
             $dimension = explode(':', $sheet->calculateWorksheetDimension());
-            $dimension[0] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($dimension[0]);
-            $dimension[0][0] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($dimension[0][0]) - 1;
-            $dimension[1] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($dimension[1]);
-            $dimension[1][0] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($dimension[1][0]) - 1;
+            $dimension[0] = Cell::coordinateFromString($dimension[0]);
+            $dimension[0][0] = Cell::columnIndexFromString($dimension[0][0]) - 1;
+            $dimension[1] = Cell::coordinateFromString($dimension[1]);
+            $dimension[1][0] = Cell::columnIndexFromString($dimension[1][0]) - 1;
 
             // row min,max
             $rowMin = $dimension[0][1];
@@ -484,7 +500,7 @@ class Html extends BaseWriter implements IWriter
                     while ($column++ < $dimension[1][0]) {
                         // Cell exists?
                         if ($sheet->cellExistsByColumnAndRow($column, $row)) {
-                            $rowData[$column] = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($column) . $row;
+                            $rowData[$column] = Cell::stringFromColumnIndex($column) . $row;
                         } else {
                             $rowData[$column] = '';
                         }
@@ -522,7 +538,7 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate sheet tabs.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
@@ -530,7 +546,7 @@ class Html extends BaseWriter implements IWriter
     {
         // Spreadsheet object known?
         if (is_null($this->spreadsheet)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Internal Spreadsheet object not set to an instance of an object.');
+            throw new WriterException('Internal Spreadsheet object not set to an instance of an object.');
         }
 
         // Fetch sheets
@@ -562,19 +578,19 @@ class Html extends BaseWriter implements IWriter
         return $html;
     }
 
-    private function extendRowsForChartsAndImages(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $row)
+    private function extendRowsForChartsAndImages(Worksheet $pSheet, $row)
     {
         $rowMax = $row;
         $colMax = 'A';
         if ($this->includeCharts) {
             foreach ($pSheet->getChartCollection() as $chart) {
-                if ($chart instanceof \PhpOffice\PhpSpreadsheet\Chart) {
+                if ($chart instanceof Chart) {
                     $chartCoordinates = $chart->getTopLeftPosition();
-                    $chartTL = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($chartCoordinates['cell']);
-                    $chartCol = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($chartTL[0]);
+                    $chartTL = Cell::coordinateFromString($chartCoordinates['cell']);
+                    $chartCol = Cell::columnIndexFromString($chartTL[0]);
                     if ($chartTL[1] > $rowMax) {
                         $rowMax = $chartTL[1];
-                        if ($chartCol > \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colMax)) {
+                        if ($chartCol > Cell::columnIndexFromString($colMax)) {
                             $colMax = $chartTL[0];
                         }
                     }
@@ -583,12 +599,12 @@ class Html extends BaseWriter implements IWriter
         }
 
         foreach ($pSheet->getDrawingCollection() as $drawing) {
-            if ($drawing instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing) {
-                $imageTL = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($drawing->getCoordinates());
-                $imageCol = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($imageTL[0]);
+            if ($drawing instanceof Drawing) {
+                $imageTL = Cell::coordinateFromString($drawing->getCoordinates());
+                $imageCol = Cell::columnIndexFromString($imageTL[0]);
                 if ($imageTL[1] > $rowMax) {
                     $rowMax = $imageTL[1];
-                    if ($imageCol > \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colMax)) {
+                    if ($imageCol > Cell::columnIndexFromString($colMax)) {
                         $colMax = $imageTL[0];
                     }
                 }
@@ -623,21 +639,21 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate image tag in cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
+     * @param Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
      * @param string $coordinates Cell coordinates
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
-    private function writeImageInCell(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $coordinates)
+    private function writeImageInCell(Worksheet $pSheet, $coordinates)
     {
         // Construct HTML
         $html = '';
 
         // Write images
         foreach ($pSheet->getDrawingCollection() as $drawing) {
-            if ($drawing instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing) {
+            if ($drawing instanceof Drawing) {
                 if ($drawing->getCoordinates() == $coordinates) {
                     $filename = $drawing->getPath();
 
@@ -681,7 +697,7 @@ class Html extends BaseWriter implements IWriter
                         $imageData . '" border="0" />';
                     $html .= '</div>';
                 }
-            } elseif ($drawing instanceof \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing) {
+            } elseif ($drawing instanceof MemoryDrawing) {
                 if ($drawing->getCoordinates() != $coordinates) {
                     continue;
                 }
@@ -706,24 +722,24 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate chart tag in cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
+     * @param Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
      * @param string $coordinates Cell coordinates
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
-    private function writeChartInCell(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $coordinates)
+    private function writeChartInCell(Worksheet $pSheet, $coordinates)
     {
         // Construct HTML
         $html = '';
 
         // Write charts
         foreach ($pSheet->getChartCollection() as $chart) {
-            if ($chart instanceof \PhpOffice\PhpSpreadsheet\Chart) {
+            if ($chart instanceof Chart) {
                 $chartCoordinates = $chart->getTopLeftPosition();
                 if ($chartCoordinates['cell'] == $coordinates) {
-                    $chartFileName = \PhpOffice\PhpSpreadsheet\Shared\File::sysGetTempDir() . '/' . uniqid() . '.png';
+                    $chartFileName = File::sysGetTempDir() . '/' . uniqid() . '.png';
                     if (!$chart->render($chartFileName)) {
                         return;
                     }
@@ -757,7 +773,7 @@ class Html extends BaseWriter implements IWriter
      *
      * @param bool $generateSurroundingHTML Generate surrounding HTML tags? (&lt;style&gt; and &lt;/style&gt;)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
@@ -765,7 +781,7 @@ class Html extends BaseWriter implements IWriter
     {
         // Spreadsheet object known?
         if (is_null($this->spreadsheet)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Internal Spreadsheet object not set to an instance of an object.');
+            throw new WriterException('Internal Spreadsheet object not set to an instance of an object.');
         }
 
         // Build CSS
@@ -801,7 +817,7 @@ class Html extends BaseWriter implements IWriter
      *
      * @param bool $generateSurroundingHTML Generate surrounding HTML style? (html { })
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return array
      */
@@ -809,7 +825,7 @@ class Html extends BaseWriter implements IWriter
     {
         // Spreadsheet object known?
         if (is_null($this->spreadsheet)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Internal Spreadsheet object not set to an instance of an object.');
+            throw new WriterException('Internal Spreadsheet object not set to an instance of an object.');
         }
 
         // Cached?
@@ -885,7 +901,7 @@ class Html extends BaseWriter implements IWriter
             $sheet->calculateColumnWidths();
 
             // col elements, initialize
-            $highestColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($sheet->getHighestColumn()) - 1;
+            $highestColumnIndex = Cell::columnIndexFromString($sheet->getHighestColumn()) - 1;
             $column = -1;
             while ($column++ < $highestColumnIndex) {
                 $this->columnWidths[$sheetIndex][$column] = 42; // approximation
@@ -894,9 +910,9 @@ class Html extends BaseWriter implements IWriter
 
             // col elements, loop through columnDimensions and set width
             foreach ($sheet->getColumnDimensions() as $columnDimension) {
-                if (($width = \PhpOffice\PhpSpreadsheet\Shared\Drawing::cellDimensionToPixels($columnDimension->getWidth(), $this->defaultFont)) >= 0) {
-                    $width = \PhpOffice\PhpSpreadsheet\Shared\Drawing::pixelsToPoints($width);
-                    $column = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($columnDimension->getColumnIndex()) - 1;
+                if (($width = SharedDrawing::cellDimensionToPixels($columnDimension->getWidth(), $this->defaultFont)) >= 0) {
+                    $width = SharedDrawing::pixelsToPoints($width);
+                    $column = Cell::columnIndexFromString($columnDimension->getColumnIndex()) - 1;
                     $this->columnWidths[$sheetIndex][$column] = $width;
                     $css['table.sheet' . $sheetIndex . ' col.col' . $column]['width'] = $width . 'pt';
 
@@ -914,7 +930,7 @@ class Html extends BaseWriter implements IWriter
             $css['table.sheet' . $sheetIndex . ' tr'] = [];
 
             if ($rowDimension->getRowHeight() == -1) {
-                $pt_height = Font::getDefaultRowHeightByFont($this->spreadsheet->getDefaultStyle()->getFont());
+                $pt_height = SharedFont::getDefaultRowHeightByFont($this->spreadsheet->getDefaultStyle()->getFont());
             } else {
                 $pt_height = $rowDimension->getRowHeight();
             }
@@ -932,7 +948,7 @@ class Html extends BaseWriter implements IWriter
                 $css['table.sheet' . $sheetIndex . ' tr.row' . $row] = [];
 
                 if ($rowDimension->getRowHeight() == -1) {
-                    $pt_height = Font::getDefaultRowHeightByFont($this->spreadsheet->getDefaultStyle()->getFont());
+                    $pt_height = SharedFont::getDefaultRowHeightByFont($this->spreadsheet->getDefaultStyle()->getFont());
                 } else {
                     $pt_height = $rowDimension->getRowHeight();
                 }
@@ -956,11 +972,11 @@ class Html extends BaseWriter implements IWriter
     /**
      * Create CSS style.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style $pStyle
+     * @param Style $pStyle
      *
      * @return array
      */
-    private function createCSSStyle(\PhpOffice\PhpSpreadsheet\Style $pStyle)
+    private function createCSSStyle(Style $pStyle)
     {
         // Construct CSS
         $css = '';
@@ -980,11 +996,11 @@ class Html extends BaseWriter implements IWriter
     /**
      * Create CSS style (\PhpOffice\PhpSpreadsheet\Style\Alignment).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Alignment $pStyle \PhpOffice\PhpSpreadsheet\Style\Alignment
+     * @param Alignment $pStyle \PhpOffice\PhpSpreadsheet\Style\Alignment
      *
      * @return array
      */
-    private function createCSSStyleAlignment(\PhpOffice\PhpSpreadsheet\Style\Alignment $pStyle)
+    private function createCSSStyleAlignment(Alignment $pStyle)
     {
         // Construct CSS
         $css = [];
@@ -1004,11 +1020,11 @@ class Html extends BaseWriter implements IWriter
     /**
      * Create CSS style (\PhpOffice\PhpSpreadsheet\Style\Font).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Font $pStyle \PhpOffice\PhpSpreadsheet\Style\Font
+     * @param Font $pStyle
      *
      * @return array
      */
-    private function createCSSStyleFont(\PhpOffice\PhpSpreadsheet\Style\Font $pStyle)
+    private function createCSSStyleFont(Font $pStyle)
     {
         // Construct CSS
         $css = [];
@@ -1017,9 +1033,9 @@ class Html extends BaseWriter implements IWriter
         if ($pStyle->getBold()) {
             $css['font-weight'] = 'bold';
         }
-        if ($pStyle->getUnderline() != \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_NONE && $pStyle->getStrikethrough()) {
+        if ($pStyle->getUnderline() != Font::UNDERLINE_NONE && $pStyle->getStrikethrough()) {
             $css['text-decoration'] = 'underline line-through';
-        } elseif ($pStyle->getUnderline() != \PhpOffice\PhpSpreadsheet\Style\Font::UNDERLINE_NONE) {
+        } elseif ($pStyle->getUnderline() != Font::UNDERLINE_NONE) {
             $css['text-decoration'] = 'underline';
         } elseif ($pStyle->getStrikethrough()) {
             $css['text-decoration'] = 'line-through';
@@ -1036,13 +1052,13 @@ class Html extends BaseWriter implements IWriter
     }
 
     /**
-     * Create CSS style (\PhpOffice\PhpSpreadsheet\Style\Borders).
+     * Create CSS style (Borders).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Borders $pStyle \PhpOffice\PhpSpreadsheet\Style\Borders
+     * @param Borders $pStyle Borders
      *
      * @return array
      */
-    private function createCSSStyleBorders(\PhpOffice\PhpSpreadsheet\Style\Borders $pStyle)
+    private function createCSSStyleBorders(Borders $pStyle)
     {
         // Construct CSS
         $css = [];
@@ -1057,13 +1073,13 @@ class Html extends BaseWriter implements IWriter
     }
 
     /**
-     * Create CSS style (\PhpOffice\PhpSpreadsheet\Style\Border).
+     * Create CSS style (Border).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Border $pStyle \PhpOffice\PhpSpreadsheet\Style\Border
+     * @param Border $pStyle Border
      *
      * @return string
      */
-    private function createCSSStyleBorder(\PhpOffice\PhpSpreadsheet\Style\Border $pStyle)
+    private function createCSSStyleBorder(Border $pStyle)
     {
         //    Create CSS - add !important to non-none border styles for merged cells
         $borderStyle = $this->mapBorderStyle($pStyle->getBorderStyle());
@@ -1073,19 +1089,19 @@ class Html extends BaseWriter implements IWriter
     }
 
     /**
-     * Create CSS style (\PhpOffice\PhpSpreadsheet\Style\Fill).
+     * Create CSS style (Fill).
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Fill $pStyle \PhpOffice\PhpSpreadsheet\Style\Fill
+     * @param Fill $pStyle Fill
      *
      * @return array
      */
-    private function createCSSStyleFill(\PhpOffice\PhpSpreadsheet\Style\Fill $pStyle)
+    private function createCSSStyleFill(Fill $pStyle)
     {
         // Construct HTML
         $css = [];
 
         // Create CSS
-        $value = $pStyle->getFillType() == \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE ?
+        $value = $pStyle->getFillType() == Fill::FILL_NONE ?
             'white' : '#' . $pStyle->getStartColor()->getRGB();
         $css['background-color'] = $value;
 
@@ -1108,9 +1124,9 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate table header.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet The worksheet for the table we are writing
+     * @param Worksheet $pSheet The worksheet for the table we are writing
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
@@ -1137,7 +1153,7 @@ class Html extends BaseWriter implements IWriter
         }
 
         // Write <col> elements
-        $highestColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($pSheet->getHighestColumn()) - 1;
+        $highestColumnIndex = Cell::columnIndexFromString($pSheet->getHighestColumn()) - 1;
         $i = -1;
         while ($i++ < $highestColumnIndex) {
             if (!$this->isPdf) {
@@ -1157,7 +1173,7 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate table footer.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function generateTableFooter()
     {
@@ -1169,16 +1185,16 @@ class Html extends BaseWriter implements IWriter
     /**
      * Generate row.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
+     * @param Worksheet $pSheet \PhpOffice\PhpSpreadsheet\Worksheet
      * @param array $pValues Array containing cells in a row
      * @param int $pRow Row number (0-based)
      * @param mixed $cellType eg: 'td'
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string
      */
-    private function generateRow(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet, array $pValues, $pRow, $cellType)
+    private function generateRow(Worksheet $pSheet, array $pValues, $pRow, $cellType)
     {
         // Construct HTML
         $html = '';
@@ -1217,7 +1233,7 @@ class Html extends BaseWriter implements IWriter
         $colNum = 0;
         foreach ($pValues as $cellAddress) {
             $cell = ($cellAddress > '') ? $pSheet->getCell($cellAddress) : '';
-            $coordinate = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($colNum) . ($pRow + 1);
+            $coordinate = Cell::stringFromColumnIndex($colNum) . ($pRow + 1);
             if (!$this->useInlineCss) {
                 $cssClass = '';
                 $cssClass = 'column' . $colNum;
@@ -1239,19 +1255,19 @@ class Html extends BaseWriter implements IWriter
             // initialize
             $cellData = '&nbsp;';
 
-            // \PhpOffice\PhpSpreadsheet\Cell
-            if ($cell instanceof \PhpOffice\PhpSpreadsheet\Cell) {
+            // Cell
+            if ($cell instanceof Cell) {
                 $cellData = '';
                 if (is_null($cell->getParent())) {
                     $cell->attach($pSheet);
                 }
                 // Value
-                if ($cell->getValue() instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+                if ($cell->getValue() instanceof RichText) {
                     // Loop through rich text elements
                     $elements = $cell->getValue()->getRichTextElements();
                     foreach ($elements as $element) {
                         // Rich text start?
-                        if ($element instanceof \PhpOffice\PhpSpreadsheet\RichText\Run) {
+                        if ($element instanceof RichText\Run) {
                             $cellData .= '<span style="' . $this->assembleCSS($this->createCSSStyleFont($element->getFont())) . '">';
 
                             if ($element->getFont()->getSuperScript()) {
@@ -1265,7 +1281,7 @@ class Html extends BaseWriter implements IWriter
                         $cellText = $element->getText();
                         $cellData .= htmlspecialchars($cellText);
 
-                        if ($element instanceof \PhpOffice\PhpSpreadsheet\RichText\Run) {
+                        if ($element instanceof RichText\Run) {
                             if ($element->getFont()->getSuperScript()) {
                                 $cellData .= '</sup>';
                             } elseif ($element->getFont()->getSubScript()) {
@@ -1277,13 +1293,13 @@ class Html extends BaseWriter implements IWriter
                     }
                 } else {
                     if ($this->preCalculateFormulas) {
-                        $cellData = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString(
+                        $cellData = NumberFormat::toFormattedString(
                             $cell->getCalculatedValue(),
                             $pSheet->getParent()->getCellXfByIndex($cell->getXfIndex())->getNumberFormat()->getFormatCode(),
                             [$this, 'formatColor']
                         );
                     } else {
-                        $cellData = \PhpOffice\PhpSpreadsheet\Style\NumberFormat::toFormattedString(
+                        $cellData = NumberFormat::toFormattedString(
                             $cell->getValue(),
                             $pSheet->getParent()->getCellXfByIndex($cell->getXfIndex())->getNumberFormat()->getFormatCode(),
                             [$this, 'formatColor']
@@ -1321,7 +1337,7 @@ class Html extends BaseWriter implements IWriter
 
                     // General horizontal alignment: Actual horizontal alignment depends on dataType
                     $sharedStyle = $pSheet->getParent()->getCellXfByIndex($cell->getXfIndex());
-                    if ($sharedStyle->getAlignment()->getHorizontal() == \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL
+                    if ($sharedStyle->getAlignment()->getHorizontal() == Alignment::HORIZONTAL_GENERAL
                         && isset($this->cssStyles['.' . $cell->getDataType()]['text-align'])
                     ) {
                         $cssClass['text-align'] = $this->cssStyles['.' . $cell->getDataType()]['text-align'];
@@ -1348,7 +1364,7 @@ class Html extends BaseWriter implements IWriter
 
                 //    Also apply style from last cell in merge to fix borders -
                 //        relies on !important for non-none border declarations in createCSSStyleBorder
-                $endCellCoord = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($colNum + $colSpan - 1) . ($pRow + $rowSpan);
+                $endCellCoord = Cell::stringFromColumnIndex($colNum + $colSpan - 1) . ($pRow + $rowSpan);
                 if (!$this->useInlineCss) {
                     $cssClass .= ' style' . $pSheet->getCell($endCellCoord)->getXfIndex();
                 }
@@ -1559,15 +1575,15 @@ class Html extends BaseWriter implements IWriter
 
             // loop through all Excel merged cells
             foreach ($sheet->getMergeCells() as $cells) {
-                list($cells) = \PhpOffice\PhpSpreadsheet\Cell::splitRange($cells);
+                list($cells) = Cell::splitRange($cells);
                 $first = $cells[0];
                 $last = $cells[1];
 
-                list($fc, $fr) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($first);
-                $fc = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($fc) - 1;
+                list($fc, $fr) = Cell::coordinateFromString($first);
+                $fc = Cell::columnIndexFromString($fc) - 1;
 
-                list($lc, $lr) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($last);
-                $lc = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($lc) - 1;
+                list($lc, $lr) = Cell::coordinateFromString($last);
+                $lc = Cell::columnIndexFromString($lc) - 1;
 
                 // loop through the individual cells in the individual merge
                 $r = $fr - 1;
@@ -1597,7 +1613,7 @@ class Html extends BaseWriter implements IWriter
 
             // Identify which rows should be omitted in HTML. These are the rows where all the cells
             //   participate in a merge and the where base cells are somewhere above.
-            $countColumns = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($sheet->getHighestColumn());
+            $countColumns = Cell::columnIndexFromString($sheet->getHighestColumn());
             foreach ($candidateSpannedRow as $rowIndex) {
                 if (isset($this->isSpannedCell[$sheetIndex][$rowIndex])) {
                     if (count($this->isSpannedCell[$sheetIndex][$rowIndex]) == $countColumns) {
@@ -1631,7 +1647,7 @@ class Html extends BaseWriter implements IWriter
         $this->spansAreCalculated = true;
     }
 
-    private function setMargins(\PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function setMargins(Worksheet $pSheet)
     {
         $htmlPage = '@page { ';
         $htmlBody = 'body { ';
diff --git a/src/PhpSpreadsheet/Writer/Ods.php b/src/PhpSpreadsheet/Writer/Ods.php
index f82d4a73..e56bdd52 100644
--- a/src/PhpSpreadsheet/Writer/Ods.php
+++ b/src/PhpSpreadsheet/Writer/Ods.php
@@ -2,7 +2,16 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Shared\File;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Content;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Meta;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\MetaInf;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Mimetype;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Settings;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Styles;
+use PhpOffice\PhpSpreadsheet\Writer\Ods\Thumbnails;
 use ZipArchive;
 
 /**
@@ -46,20 +55,20 @@ class Ods extends BaseWriter implements IWriter
     /**
      * Create a new Ods.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function __construct(Spreadsheet $spreadsheet)
     {
         $this->setSpreadsheet($spreadsheet);
 
         $writerPartsArray = [
-            'content' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Content::class,
-            'meta' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Meta::class,
-            'meta_inf' => \PhpOffice\PhpSpreadsheet\Writer\Ods\MetaInf::class,
-            'mimetype' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Mimetype::class,
-            'settings' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Settings::class,
-            'styles' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Styles::class,
-            'thumbnails' => \PhpOffice\PhpSpreadsheet\Writer\Ods\Thumbnails::class,
+            'content' => Content::class,
+            'meta' => Meta::class,
+            'meta_inf' => MetaInf::class,
+            'mimetype' => Mimetype::class,
+            'settings' => Settings::class,
+            'styles' => Styles::class,
+            'thumbnails' => Thumbnails::class,
         ];
 
         foreach ($writerPartsArray as $writer => $class) {
@@ -88,12 +97,12 @@ class Ods extends BaseWriter implements IWriter
      *
      * @param string $pFilename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     public function save($pFilename)
     {
         if (!$this->spreadSheet) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('PhpSpreadsheet object unassigned.');
+            throw new WriterException('PhpSpreadsheet object unassigned.');
         }
 
         // garbage collect
@@ -102,7 +111,7 @@ class Ods extends BaseWriter implements IWriter
         // If $pFilename is php://output or php://stdout, make it a temporary file...
         $originalFilename = $pFilename;
         if (strtolower($pFilename) == 'php://output' || strtolower($pFilename) == 'php://stdout') {
-            $pFilename = @tempnam(\PhpOffice\PhpSpreadsheet\Shared\File::sysGetTempDir(), 'phpxltmp');
+            $pFilename = @tempnam(File::sysGetTempDir(), 'phpxltmp');
             if ($pFilename == '') {
                 $pFilename = $originalFilename;
             }
@@ -120,13 +129,13 @@ class Ods extends BaseWriter implements IWriter
 
         // Close file
         if ($zip->close() === false) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not close zip file $pFilename.");
+            throw new WriterException("Could not close zip file $pFilename.");
         }
 
         // If a temporary file was used, copy it to the correct file stream
         if ($originalFilename != $pFilename) {
             if (copy($pFilename, $originalFilename) === false) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not copy temporary zip file $pFilename to $originalFilename.");
+                throw new WriterException("Could not copy temporary zip file $pFilename to $originalFilename.");
             }
             @unlink($pFilename);
         }
@@ -137,7 +146,7 @@ class Ods extends BaseWriter implements IWriter
      *
      * @param string $pFilename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return ZipArchive
      */
@@ -152,7 +161,7 @@ class Ods extends BaseWriter implements IWriter
         // Try opening the ZIP file
         if ($zip->open($pFilename, ZipArchive::OVERWRITE) !== true) {
             if ($zip->open($pFilename, ZipArchive::CREATE) !== true) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not open $pFilename for writing.");
+                throw new WriterException("Could not open $pFilename for writing.");
             }
         }
 
@@ -162,7 +171,7 @@ class Ods extends BaseWriter implements IWriter
     /**
      * Get Spreadsheet object.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return Spreadsheet
      */
@@ -171,19 +180,19 @@ class Ods extends BaseWriter implements IWriter
         if ($this->spreadSheet !== null) {
             return $this->spreadSheet;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('No PhpSpreadsheet assigned.');
+        throw new WriterException('No PhpSpreadsheet assigned.');
     }
 
     /**
      * Set Spreadsheet object.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet PhpSpreadsheet object
+     * @param Spreadsheet $spreadsheet PhpSpreadsheet object
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return self
      */
-    public function setSpreadsheet(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function setSpreadsheet(Spreadsheet $spreadsheet)
     {
         $this->spreadSheet = $spreadsheet;
 
diff --git a/src/PhpSpreadsheet/Writer/Ods/Cell/Comment.php b/src/PhpSpreadsheet/Writer/Ods/Cell/Comment.php
index 0ccf5618..f38a3c06 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Cell/Comment.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Cell/Comment.php
@@ -2,7 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods\Cell;
 
-/**
+/*
  * PhpSpreadsheet.
  *
  * Copyright (c) 2006 - 2015 PhpSpreadsheet
@@ -26,6 +26,8 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Ods\Cell;
  * @copyright  Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
 
 /**
  * @category   PhpSpreadsheet
@@ -35,7 +37,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Ods\Cell;
  */
 class Comment
 {
-    public static function write(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Cell $cell)
+    public static function write(XMLWriter $objWriter, Cell $cell)
     {
         $comments = $cell->getWorksheet()->getComments();
         if (!isset($comments[$cell->getCoordinate()])) {
diff --git a/src/PhpSpreadsheet/Writer/Ods/Meta.php b/src/PhpSpreadsheet/Writer/Ods/Meta.php
index 4a57ac69..d00c479b 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Meta.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Meta.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,13 +32,13 @@ class Meta extends WriterPart
     /**
      * Write meta.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function write(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function write(Spreadsheet $spreadsheet = null)
     {
         if (!$spreadsheet) {
             $spreadsheet = $this->getParentWriter()->getSpreadsheet();
@@ -43,9 +46,9 @@ class Meta extends WriterPart
 
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Ods/MetaInf.php b/src/PhpSpreadsheet/Writer/Ods/MetaInf.php
index c712e7cd..9cd0dc6c 100644
--- a/src/PhpSpreadsheet/Writer/Ods/MetaInf.php
+++ b/src/PhpSpreadsheet/Writer/Ods/MetaInf.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,13 +32,13 @@ class MetaInf extends WriterPart
     /**
      * Write META-INF/manifest.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeManifest(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function writeManifest(Spreadsheet $spreadsheet = null)
     {
         if (!$spreadsheet) {
             $spreadsheet = $this->getParentWriter()->getSpreadsheet();
@@ -43,9 +46,9 @@ class MetaInf extends WriterPart
 
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Ods/Mimetype.php b/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
index f3bf03b5..7733f4d8 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Mimetype.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -27,13 +29,13 @@ class Mimetype extends WriterPart
     /**
      * Write mimetype to plain text format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function write(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function write(Spreadsheet $spreadsheet = null)
     {
         return 'application/vnd.oasis.opendocument.spreadsheet';
     }
diff --git a/src/PhpSpreadsheet/Writer/Ods/Settings.php b/src/PhpSpreadsheet/Writer/Ods/Settings.php
index dd77ae54..cea7c725 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Settings.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Settings.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,13 +32,13 @@ class Settings extends WriterPart
     /**
      * Write settings.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function write(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function write(Spreadsheet $spreadsheet = null)
     {
         if (!$spreadsheet) {
             $spreadsheet = $this->getParentWriter()->getSpreadsheet();
@@ -43,9 +46,9 @@ class Settings extends WriterPart
 
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Ods/Styles.php b/src/PhpSpreadsheet/Writer/Ods/Styles.php
index 5219f106..a9ea8e86 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Styles.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Styles.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,13 +32,13 @@ class Styles extends WriterPart
     /**
      * Write styles.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function write(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function write(Spreadsheet $spreadsheet = null)
     {
         if (!$spreadsheet) {
             $spreadsheet = $this->getParentWriter()->getSpreadsheet();
@@ -43,9 +46,9 @@ class Styles extends WriterPart
 
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php b/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
index df5642fb..b2e38ea5 100644
--- a/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
+++ b/src/PhpSpreadsheet/Writer/Ods/Thumbnails.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,13 +31,13 @@ class Thumbnails extends WriterPart
     /**
      * Write Thumbnails/thumbnail.png to PNG format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeThumbnail(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet = null)
+    public function writeThumbnail(Spreadsheet $spreadsheet = null)
     {
         return '';
     }
diff --git a/src/PhpSpreadsheet/Writer/Ods/WriterPart.php b/src/PhpSpreadsheet/Writer/Ods/WriterPart.php
index b07b38cb..04fd0fdb 100644
--- a/src/PhpSpreadsheet/Writer/Ods/WriterPart.php
+++ b/src/PhpSpreadsheet/Writer/Ods/WriterPart.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Ods;
 
+use PhpOffice\PhpSpreadsheet\Writer\Ods;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,7 +31,7 @@ abstract class WriterPart
     /**
      * Parent Ods object.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Writer\Ods
+     * @var Ods
      */
     private $parentWriter;
 
@@ -38,7 +40,7 @@ abstract class WriterPart
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Writer\Ods
+     * @return Ods
      */
     public function getParentWriter()
     {
@@ -48,9 +50,9 @@ abstract class WriterPart
     /**
      * Set parent Ods writer.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Writer\Ods $writer
+     * @param Ods $writer
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Writer\Ods $writer)
+    public function __construct(Ods $writer)
     {
         $this->parentWriter = $writer;
     }
diff --git a/src/PhpSpreadsheet/Writer/Pdf.php b/src/PhpSpreadsheet/Writer/Pdf.php
index eeec2334..48e585b2 100644
--- a/src/PhpSpreadsheet/Writer/Pdf.php
+++ b/src/PhpSpreadsheet/Writer/Pdf.php
@@ -2,6 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Settings;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 /**
@@ -38,13 +39,13 @@ class Pdf implements IWriter
     /**
      * Instantiate a new renderer of the configured type within this container class.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet PhpSpreadsheet object
+     * @param Spreadsheet $spreadsheet PhpSpreadsheet object
      *
      * @throws Exception when PDF library is not configured
      */
     public function __construct(Spreadsheet $spreadsheet)
     {
-        $pdfLibraryName = \PhpOffice\PhpSpreadsheet\Settings::getPdfRendererName();
+        $pdfLibraryName = Settings::getPdfRendererName();
         if (is_null($pdfLibraryName)) {
             throw new Exception('PDF Rendering library has not been defined.');
         }
diff --git a/src/PhpSpreadsheet/Writer/Pdf/Core.php b/src/PhpSpreadsheet/Writer/Pdf/Core.php
index 084b514c..d8eeb00a 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/Core.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/Core.php
@@ -2,6 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+use PhpOffice\PhpSpreadsheet\Writer\Html;
+
 /**
  *  Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -24,7 +31,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
  *  @copyright   Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  *  @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
+abstract class Core extends Html
 {
     /**
      * Temporary storage directory.
@@ -67,84 +74,84 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
      * @var array
      */
     protected static $paperSizes = [
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER => 'LETTER', //    (8.5 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER_SMALL => 'LETTER', //    (8.5 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_TABLOID => [792.00, 1224.00], //    (11 in. by 17 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LEDGER => [1224.00, 792.00], //    (17 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LEGAL => 'LEGAL', //    (8.5 in. by 14 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STATEMENT => [396.00, 612.00], //    (5.5 in. by 8.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_EXECUTIVE => 'EXECUTIVE', //    (7.25 in. by 10.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A3 => 'A3', //    (297 mm by 420 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4 => 'A4', //    (210 mm by 297 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4_SMALL => 'A4', //    (210 mm by 297 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A5 => 'A5', //    (148 mm by 210 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_B4 => 'B4', //    (250 mm by 353 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_B5 => 'B5', //    (176 mm by 250 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_FOLIO => 'FOLIO', //    (8.5 in. by 13 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_QUARTO => [609.45, 779.53], //    (215 mm by 275 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STANDARD_1 => [720.00, 1008.00], //    (10 in. by 14 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STANDARD_2 => [792.00, 1224.00], //    (11 in. by 17 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NOTE => 'LETTER', //    (8.5 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NO9_ENVELOPE => [279.00, 639.00], //    (3.875 in. by 8.875 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NO10_ENVELOPE => [297.00, 684.00], //    (4.125 in. by 9.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NO11_ENVELOPE => [324.00, 747.00], //    (4.5 in. by 10.375 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NO12_ENVELOPE => [342.00, 792.00], //    (4.75 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_NO14_ENVELOPE => [360.00, 828.00], //    (5 in. by 11.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C => [1224.00, 1584.00], //    (17 in. by 22 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_D => [1584.00, 2448.00], //    (22 in. by 34 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_E => [2448.00, 3168.00], //    (34 in. by 44 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_DL_ENVELOPE => [311.81, 623.62], //    (110 mm by 220 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C5_ENVELOPE => 'C5', //    (162 mm by 229 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C3_ENVELOPE => 'C3', //    (324 mm by 458 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C4_ENVELOPE => 'C4', //    (229 mm by 324 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C6_ENVELOPE => 'C6', //    (114 mm by 162 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_C65_ENVELOPE => [323.15, 649.13], //    (114 mm by 229 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_B4_ENVELOPE => 'B4', //    (250 mm by 353 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_B5_ENVELOPE => 'B5', //    (176 mm by 250 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_B6_ENVELOPE => [498.90, 354.33], //    (176 mm by 125 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_ITALY_ENVELOPE => [311.81, 651.97], //    (110 mm by 230 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_MONARCH_ENVELOPE => [279.00, 540.00], //    (3.875 in. by 7.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_6_3_4_ENVELOPE => [261.00, 468.00], //    (3.625 in. by 6.5 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_US_STANDARD_FANFOLD => [1071.00, 792.00], //    (14.875 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_GERMAN_STANDARD_FANFOLD => [612.00, 864.00], //    (8.5 in. by 12 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_GERMAN_LEGAL_FANFOLD => 'FOLIO', //    (8.5 in. by 13 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_ISO_B4 => 'B4', //    (250 mm by 353 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_JAPANESE_DOUBLE_POSTCARD => [566.93, 419.53], //    (200 mm by 148 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STANDARD_PAPER_1 => [648.00, 792.00], //    (9 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STANDARD_PAPER_2 => [720.00, 792.00], //    (10 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_STANDARD_PAPER_3 => [1080.00, 792.00], //    (15 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_INVITE_ENVELOPE => [623.62, 623.62], //    (220 mm by 220 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER_EXTRA_PAPER => [667.80, 864.00], //    (9.275 in. by 12 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LEGAL_EXTRA_PAPER => [667.80, 1080.00], //    (9.275 in. by 15 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_TABLOID_EXTRA_PAPER => [841.68, 1296.00], //    (11.69 in. by 18 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4_EXTRA_PAPER => [668.98, 912.76], //    (236 mm by 322 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER_TRANSVERSE_PAPER => [595.80, 792.00], //    (8.275 in. by 11 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4_TRANSVERSE_PAPER => 'A4', //    (210 mm by 297 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER_EXTRA_TRANSVERSE_PAPER => [667.80, 864.00], //    (9.275 in. by 12 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_SUPERA_SUPERA_A4_PAPER => [643.46, 1009.13], //    (227 mm by 356 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_SUPERB_SUPERB_A3_PAPER => [864.57, 1380.47], //    (305 mm by 487 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_LETTER_PLUS_PAPER => [612.00, 913.68], //    (8.5 in. by 12.69 in.)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A4_PLUS_PAPER => [595.28, 935.43], //    (210 mm by 330 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A5_TRANSVERSE_PAPER => 'A5', //    (148 mm by 210 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_JIS_B5_TRANSVERSE_PAPER => [515.91, 728.50], //    (182 mm by 257 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A3_EXTRA_PAPER => [912.76, 1261.42], //    (322 mm by 445 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A5_EXTRA_PAPER => [493.23, 666.14], //    (174 mm by 235 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_ISO_B5_EXTRA_PAPER => [569.76, 782.36], //    (201 mm by 276 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A2_PAPER => 'A2', //    (420 mm by 594 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A3_TRANSVERSE_PAPER => 'A3', //    (297 mm by 420 mm)
-        \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_A3_EXTRA_TRANSVERSE_PAPER => [912.76, 1261.42], //    (322 mm by 445 mm)
+        PageSetup::PAPERSIZE_LETTER => 'LETTER', //    (8.5 in. by 11 in.)
+        PageSetup::PAPERSIZE_LETTER_SMALL => 'LETTER', //    (8.5 in. by 11 in.)
+        PageSetup::PAPERSIZE_TABLOID => [792.00, 1224.00], //    (11 in. by 17 in.)
+        PageSetup::PAPERSIZE_LEDGER => [1224.00, 792.00], //    (17 in. by 11 in.)
+        PageSetup::PAPERSIZE_LEGAL => 'LEGAL', //    (8.5 in. by 14 in.)
+        PageSetup::PAPERSIZE_STATEMENT => [396.00, 612.00], //    (5.5 in. by 8.5 in.)
+        PageSetup::PAPERSIZE_EXECUTIVE => 'EXECUTIVE', //    (7.25 in. by 10.5 in.)
+        PageSetup::PAPERSIZE_A3 => 'A3', //    (297 mm by 420 mm)
+        PageSetup::PAPERSIZE_A4 => 'A4', //    (210 mm by 297 mm)
+        PageSetup::PAPERSIZE_A4_SMALL => 'A4', //    (210 mm by 297 mm)
+        PageSetup::PAPERSIZE_A5 => 'A5', //    (148 mm by 210 mm)
+        PageSetup::PAPERSIZE_B4 => 'B4', //    (250 mm by 353 mm)
+        PageSetup::PAPERSIZE_B5 => 'B5', //    (176 mm by 250 mm)
+        PageSetup::PAPERSIZE_FOLIO => 'FOLIO', //    (8.5 in. by 13 in.)
+        PageSetup::PAPERSIZE_QUARTO => [609.45, 779.53], //    (215 mm by 275 mm)
+        PageSetup::PAPERSIZE_STANDARD_1 => [720.00, 1008.00], //    (10 in. by 14 in.)
+        PageSetup::PAPERSIZE_STANDARD_2 => [792.00, 1224.00], //    (11 in. by 17 in.)
+        PageSetup::PAPERSIZE_NOTE => 'LETTER', //    (8.5 in. by 11 in.)
+        PageSetup::PAPERSIZE_NO9_ENVELOPE => [279.00, 639.00], //    (3.875 in. by 8.875 in.)
+        PageSetup::PAPERSIZE_NO10_ENVELOPE => [297.00, 684.00], //    (4.125 in. by 9.5 in.)
+        PageSetup::PAPERSIZE_NO11_ENVELOPE => [324.00, 747.00], //    (4.5 in. by 10.375 in.)
+        PageSetup::PAPERSIZE_NO12_ENVELOPE => [342.00, 792.00], //    (4.75 in. by 11 in.)
+        PageSetup::PAPERSIZE_NO14_ENVELOPE => [360.00, 828.00], //    (5 in. by 11.5 in.)
+        PageSetup::PAPERSIZE_C => [1224.00, 1584.00], //    (17 in. by 22 in.)
+        PageSetup::PAPERSIZE_D => [1584.00, 2448.00], //    (22 in. by 34 in.)
+        PageSetup::PAPERSIZE_E => [2448.00, 3168.00], //    (34 in. by 44 in.)
+        PageSetup::PAPERSIZE_DL_ENVELOPE => [311.81, 623.62], //    (110 mm by 220 mm)
+        PageSetup::PAPERSIZE_C5_ENVELOPE => 'C5', //    (162 mm by 229 mm)
+        PageSetup::PAPERSIZE_C3_ENVELOPE => 'C3', //    (324 mm by 458 mm)
+        PageSetup::PAPERSIZE_C4_ENVELOPE => 'C4', //    (229 mm by 324 mm)
+        PageSetup::PAPERSIZE_C6_ENVELOPE => 'C6', //    (114 mm by 162 mm)
+        PageSetup::PAPERSIZE_C65_ENVELOPE => [323.15, 649.13], //    (114 mm by 229 mm)
+        PageSetup::PAPERSIZE_B4_ENVELOPE => 'B4', //    (250 mm by 353 mm)
+        PageSetup::PAPERSIZE_B5_ENVELOPE => 'B5', //    (176 mm by 250 mm)
+        PageSetup::PAPERSIZE_B6_ENVELOPE => [498.90, 354.33], //    (176 mm by 125 mm)
+        PageSetup::PAPERSIZE_ITALY_ENVELOPE => [311.81, 651.97], //    (110 mm by 230 mm)
+        PageSetup::PAPERSIZE_MONARCH_ENVELOPE => [279.00, 540.00], //    (3.875 in. by 7.5 in.)
+        PageSetup::PAPERSIZE_6_3_4_ENVELOPE => [261.00, 468.00], //    (3.625 in. by 6.5 in.)
+        PageSetup::PAPERSIZE_US_STANDARD_FANFOLD => [1071.00, 792.00], //    (14.875 in. by 11 in.)
+        PageSetup::PAPERSIZE_GERMAN_STANDARD_FANFOLD => [612.00, 864.00], //    (8.5 in. by 12 in.)
+        PageSetup::PAPERSIZE_GERMAN_LEGAL_FANFOLD => 'FOLIO', //    (8.5 in. by 13 in.)
+        PageSetup::PAPERSIZE_ISO_B4 => 'B4', //    (250 mm by 353 mm)
+        PageSetup::PAPERSIZE_JAPANESE_DOUBLE_POSTCARD => [566.93, 419.53], //    (200 mm by 148 mm)
+        PageSetup::PAPERSIZE_STANDARD_PAPER_1 => [648.00, 792.00], //    (9 in. by 11 in.)
+        PageSetup::PAPERSIZE_STANDARD_PAPER_2 => [720.00, 792.00], //    (10 in. by 11 in.)
+        PageSetup::PAPERSIZE_STANDARD_PAPER_3 => [1080.00, 792.00], //    (15 in. by 11 in.)
+        PageSetup::PAPERSIZE_INVITE_ENVELOPE => [623.62, 623.62], //    (220 mm by 220 mm)
+        PageSetup::PAPERSIZE_LETTER_EXTRA_PAPER => [667.80, 864.00], //    (9.275 in. by 12 in.)
+        PageSetup::PAPERSIZE_LEGAL_EXTRA_PAPER => [667.80, 1080.00], //    (9.275 in. by 15 in.)
+        PageSetup::PAPERSIZE_TABLOID_EXTRA_PAPER => [841.68, 1296.00], //    (11.69 in. by 18 in.)
+        PageSetup::PAPERSIZE_A4_EXTRA_PAPER => [668.98, 912.76], //    (236 mm by 322 mm)
+        PageSetup::PAPERSIZE_LETTER_TRANSVERSE_PAPER => [595.80, 792.00], //    (8.275 in. by 11 in.)
+        PageSetup::PAPERSIZE_A4_TRANSVERSE_PAPER => 'A4', //    (210 mm by 297 mm)
+        PageSetup::PAPERSIZE_LETTER_EXTRA_TRANSVERSE_PAPER => [667.80, 864.00], //    (9.275 in. by 12 in.)
+        PageSetup::PAPERSIZE_SUPERA_SUPERA_A4_PAPER => [643.46, 1009.13], //    (227 mm by 356 mm)
+        PageSetup::PAPERSIZE_SUPERB_SUPERB_A3_PAPER => [864.57, 1380.47], //    (305 mm by 487 mm)
+        PageSetup::PAPERSIZE_LETTER_PLUS_PAPER => [612.00, 913.68], //    (8.5 in. by 12.69 in.)
+        PageSetup::PAPERSIZE_A4_PLUS_PAPER => [595.28, 935.43], //    (210 mm by 330 mm)
+        PageSetup::PAPERSIZE_A5_TRANSVERSE_PAPER => 'A5', //    (148 mm by 210 mm)
+        PageSetup::PAPERSIZE_JIS_B5_TRANSVERSE_PAPER => [515.91, 728.50], //    (182 mm by 257 mm)
+        PageSetup::PAPERSIZE_A3_EXTRA_PAPER => [912.76, 1261.42], //    (322 mm by 445 mm)
+        PageSetup::PAPERSIZE_A5_EXTRA_PAPER => [493.23, 666.14], //    (174 mm by 235 mm)
+        PageSetup::PAPERSIZE_ISO_B5_EXTRA_PAPER => [569.76, 782.36], //    (201 mm by 276 mm)
+        PageSetup::PAPERSIZE_A2_PAPER => 'A2', //    (420 mm by 594 mm)
+        PageSetup::PAPERSIZE_A3_TRANSVERSE_PAPER => 'A3', //    (297 mm by 420 mm)
+        PageSetup::PAPERSIZE_A3_EXTRA_TRANSVERSE_PAPER => [912.76, 1261.42], //    (322 mm by 445 mm)
     ];
 
     /**
      * Create a new PDF Writer instance.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet Spreadsheet object
+     * @param Spreadsheet $spreadsheet Spreadsheet object
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function __construct(Spreadsheet $spreadsheet)
     {
         parent::__construct($spreadsheet);
         $this->setUseInlineCss(true);
-        $this->tempDir = \PhpOffice\PhpSpreadsheet\Shared\File::sysGetTempDir();
+        $this->tempDir = File::sysGetTempDir();
     }
 
     /**
@@ -186,7 +193,7 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
     /**
      * Set Paper Size.
      *
-     * @param string $pValue Paper size see \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::PAPERSIZE_*
+     * @param string $pValue Paper size see PageSetup::PAPERSIZE_*
      *
      * @return self
      */
@@ -210,7 +217,7 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
     /**
      * Set Orientation.
      *
-     * @param string $pValue Page orientation see \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_*
+     * @param string $pValue Page orientation see PageSetup::ORIENTATION_*
      *
      * @return self
      */
@@ -236,7 +243,7 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
      *
      * @param string $pValue Temporary storage directory
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception when directory does not exist
+     * @throws WriterException when directory does not exist
      *
      * @return self
      */
@@ -245,7 +252,7 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
         if (is_dir($pValue)) {
             $this->tempDir = $pValue;
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Directory does not exist: $pValue");
+            throw new WriterException("Directory does not exist: $pValue");
         }
 
         return $this;
@@ -256,20 +263,20 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
      *
      * @param string $pFilename Name of the file to save as
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     protected function prepareForSave($pFilename)
     {
         //  garbage collect
         $this->spreadsheet->garbageCollect();
 
-        $this->saveArrayReturnType = \PhpOffice\PhpSpreadsheet\Calculation::getArrayReturnType();
-        \PhpOffice\PhpSpreadsheet\Calculation::setArrayReturnType(\PhpOffice\PhpSpreadsheet\Calculation::RETURN_ARRAY_AS_VALUE);
+        $this->saveArrayReturnType = Calculation::getArrayReturnType();
+        Calculation::setArrayReturnType(Calculation::RETURN_ARRAY_AS_VALUE);
 
         //  Open file
         $fileHandle = fopen($pFilename, 'w');
         if ($fileHandle === false) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not open file $pFilename for writing.");
+            throw new WriterException("Could not open file $pFilename for writing.");
         }
 
         //  Set PDF
@@ -285,13 +292,13 @@ abstract class Core extends \PhpOffice\PhpSpreadsheet\Writer\Html
      *
      * @param resource $fileHandle
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     protected function restoreStateAfterSave($fileHandle)
     {
         //  Close file
         fclose($fileHandle);
 
-        \PhpOffice\PhpSpreadsheet\Calculation::setArrayReturnType($this->saveArrayReturnType);
+        Calculation::setArrayReturnType($this->saveArrayReturnType);
     }
 }
diff --git a/src/PhpSpreadsheet/Writer/Pdf/DomPDF.php b/src/PhpSpreadsheet/Writer/Pdf/DomPDF.php
index 2ddba79e..75456b8b 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/DomPDF.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/DomPDF.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Writer\IWriter;
+
 /**
  *  Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
  *  @copyright   Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  *  @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class DomPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
+class DomPDF extends Core implements IWriter
 {
     /**
      * Save Spreadsheet to file.
@@ -43,12 +46,12 @@ class DomPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
         //  Check for paper size and page orientation
         if (is_null($this->getSheetIndex())) {
             $orientation = ($this->spreadsheet->getSheet(0)->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet(0)->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet(0)->getPageMargins();
         } else {
             $orientation = ($this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageMargins();
         }
@@ -57,8 +60,8 @@ class DomPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
 
         //  Override Page Orientation
         if (!is_null($this->getOrientation())) {
-            $orientation = ($this->getOrientation() == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_DEFAULT)
-                ? \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_PORTRAIT
+            $orientation = ($this->getOrientation() == PageSetup::ORIENTATION_DEFAULT)
+                ? PageSetup::ORIENTATION_PORTRAIT
                 : $this->getOrientation();
         }
         //  Override Paper Size
diff --git a/src/PhpSpreadsheet/Writer/Pdf/MPDF.php b/src/PhpSpreadsheet/Writer/Pdf/MPDF.php
index 06cb83e1..425b132e 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/MPDF.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/MPDF.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Writer\IWriter;
+
 /**
  *  Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -24,7 +28,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
  *  @copyright   Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  *  @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class MPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
+class MPDF extends Core implements IWriter
 {
     /**
      * Save Spreadsheet to file.
@@ -32,7 +36,7 @@ class MPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
      * @param string $pFilename Name of the file to save as
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
-     * @throws \PhpOffice\PhpSpreadsheet\Exception
+     * @throws PhpSpreadsheetException
      */
     public function save($pFilename)
     {
@@ -44,12 +48,12 @@ class MPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
         //  Check for paper size and page orientation
         if (null === $this->getSheetIndex()) {
             $orientation = ($this->spreadsheet->getSheet(0)->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet(0)->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet(0)->getPageMargins();
         } else {
             $orientation = ($this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageMargins();
         }
@@ -57,8 +61,8 @@ class MPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
 
         //  Override Page Orientation
         if (null !== $this->getOrientation()) {
-            $orientation = ($this->getOrientation() == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_DEFAULT)
-                ? \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_PORTRAIT
+            $orientation = ($this->getOrientation() == PageSetup::ORIENTATION_DEFAULT)
+                ? PageSetup::ORIENTATION_PORTRAIT
                 : $this->getOrientation();
         }
         $orientation = strtoupper($orientation);
diff --git a/src/PhpSpreadsheet/Writer/Pdf/TcPDF.php b/src/PhpSpreadsheet/Writer/Pdf/TcPDF.php
index 858ff27e..33fc48a0 100644
--- a/src/PhpSpreadsheet/Writer/Pdf/TcPDF.php
+++ b/src/PhpSpreadsheet/Writer/Pdf/TcPDF.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
 
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Writer\IWriter;
+
 /**
  *  Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -24,7 +27,7 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Pdf;
  *  @copyright   Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  *  @license     http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
-class TcPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
+class TcPDF extends Core implements IWriter
 {
     /**
      * Save Spreadsheet to file.
@@ -43,19 +46,19 @@ class TcPDF extends Core implements \PhpOffice\PhpSpreadsheet\Writer\IWriter
         //  Check for paper size and page orientation
         if (is_null($this->getSheetIndex())) {
             $orientation = ($this->spreadsheet->getSheet(0)->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet(0)->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet(0)->getPageMargins();
         } else {
             $orientation = ($this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getOrientation()
-                == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
+                == PageSetup::ORIENTATION_LANDSCAPE) ? 'L' : 'P';
             $printPaperSize = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageSetup()->getPaperSize();
             $printMargins = $this->spreadsheet->getSheet($this->getSheetIndex())->getPageMargins();
         }
 
         //  Override Page Orientation
         if (!is_null($this->getOrientation())) {
-            $orientation = ($this->getOrientation() == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE)
+            $orientation = ($this->getOrientation() == PageSetup::ORIENTATION_LANDSCAPE)
                 ? 'L'
                 : 'P';
         }
diff --git a/src/PhpSpreadsheet/Writer/Xls.php b/src/PhpSpreadsheet/Writer/Xls.php
index 30698647..8f08ba48 100644
--- a/src/PhpSpreadsheet/Writer/Xls.php
+++ b/src/PhpSpreadsheet/Writer/Xls.php
@@ -2,6 +2,28 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\Drawing as SharedDrawing;
+use PhpOffice\PhpSpreadsheet\Shared\Escher;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip;
+use PhpOffice\PhpSpreadsheet\Shared\OLE;
+use PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\File;
+use PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\Root;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use RuntimeException;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,7 +51,7 @@ class Xls extends BaseWriter implements IWriter
     /**
      * PhpSpreadsheet object.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheet;
 
@@ -92,9 +114,9 @@ class Xls extends BaseWriter implements IWriter
     /**
      * Create a new Xls Writer.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet PhpSpreadsheet object
+     * @param Spreadsheet $spreadsheet PhpSpreadsheet object
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function __construct(Spreadsheet $spreadsheet)
     {
         $this->spreadsheet = $spreadsheet;
 
@@ -113,10 +135,10 @@ class Xls extends BaseWriter implements IWriter
         // garbage collect
         $this->spreadsheet->garbageCollect();
 
-        $saveDebugLog = \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->getWriteDebugLog();
-        \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog(false);
-        $saveDateReturnType = \PhpOffice\PhpSpreadsheet\Calculation\Functions::getReturnDateType();
-        \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType(\PhpOffice\PhpSpreadsheet\Calculation\Functions::RETURNDATE_EXCEL);
+        $saveDebugLog = Calculation::getInstance($this->spreadsheet)->getDebugLog()->getWriteDebugLog();
+        Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog(false);
+        $saveDateReturnType = Functions::getReturnDateType();
+        Functions::setReturnDateType(Functions::RETURNDATE_EXCEL);
 
         // initialize colors array
         $this->colors = [];
@@ -151,10 +173,10 @@ class Xls extends BaseWriter implements IWriter
             foreach ($this->writerWorksheets[$i]->phpSheet->getCoordinates() as $coordinate) {
                 $cell = $this->writerWorksheets[$i]->phpSheet->getCell($coordinate);
                 $cVal = $cell->getValue();
-                if ($cVal instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+                if ($cVal instanceof RichText) {
                     $elements = $cVal->getRichTextElements();
                     foreach ($elements as $element) {
-                        if ($element instanceof \PhpOffice\PhpSpreadsheet\RichText\Run) {
+                        if ($element instanceof RichText\Run) {
                             $font = $element->getFont();
                             $this->writerWorksheets[$i]->fontHashIndex[$font->getHashCode()] = $this->writerWorkbook->addFont($font);
                         }
@@ -165,7 +187,7 @@ class Xls extends BaseWriter implements IWriter
 
         // initialize OLE file
         $workbookStreamName = 'Workbook';
-        $OLE = new \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\File(\PhpOffice\PhpSpreadsheet\Shared\OLE::ascToUcs($workbookStreamName));
+        $OLE = new File(OLE::ascToUcs($workbookStreamName));
 
         // Write the worksheet streams before the global workbook stream,
         // because the byte sizes of these are needed in the global workbook stream
@@ -186,14 +208,14 @@ class Xls extends BaseWriter implements IWriter
         $this->documentSummaryInformation = $this->writeDocumentSummaryInformation();
         // initialize OLE Document Summary Information
         if (isset($this->documentSummaryInformation) && !empty($this->documentSummaryInformation)) {
-            $OLE_DocumentSummaryInformation = new \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\File(\PhpOffice\PhpSpreadsheet\Shared\OLE::ascToUcs(chr(5) . 'DocumentSummaryInformation'));
+            $OLE_DocumentSummaryInformation = new File(OLE::ascToUcs(chr(5) . 'DocumentSummaryInformation'));
             $OLE_DocumentSummaryInformation->append($this->documentSummaryInformation);
         }
 
         $this->summaryInformation = $this->writeSummaryInformation();
         // initialize OLE Summary Information
         if (isset($this->summaryInformation) && !empty($this->summaryInformation)) {
-            $OLE_SummaryInformation = new \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\File(\PhpOffice\PhpSpreadsheet\Shared\OLE::ascToUcs(chr(5) . 'SummaryInformation'));
+            $OLE_SummaryInformation = new File(OLE::ascToUcs(chr(5) . 'SummaryInformation'));
             $OLE_SummaryInformation->append($this->summaryInformation);
         }
 
@@ -208,12 +230,12 @@ class Xls extends BaseWriter implements IWriter
             $arrRootData[] = $OLE_DocumentSummaryInformation;
         }
 
-        $root = new \PhpOffice\PhpSpreadsheet\Shared\OLE\PPS\Root(time(), time(), $arrRootData);
+        $root = new Root(time(), time(), $arrRootData);
         // save the OLE file
         $res = $root->save($pFilename);
 
-        \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType($saveDateReturnType);
-        \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
+        Functions::setReturnDateType($saveDateReturnType);
+        Calculation::getInstance($this->spreadsheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
     }
 
     /**
@@ -239,10 +261,10 @@ class Xls extends BaseWriter implements IWriter
             }
 
             // create intermediate Escher object
-            $escher = new \PhpOffice\PhpSpreadsheet\Shared\Escher();
+            $escher = new Escher();
 
             // dgContainer
-            $dgContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer();
+            $dgContainer = new DgContainer();
 
             // set the drawing index (we use sheet index + 1)
             $dgId = $sheet->getParent()->getIndex($sheet) + 1;
@@ -250,11 +272,11 @@ class Xls extends BaseWriter implements IWriter
             $escher->setDgContainer($dgContainer);
 
             // spgrContainer
-            $spgrContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer();
+            $spgrContainer = new SpgrContainer();
             $dgContainer->setSpgrContainer($spgrContainer);
 
             // add one shape which is the group shape
-            $spContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer();
+            $spContainer = new SpContainer();
             $spContainer->setSpgr(true);
             $spContainer->setSpType(0);
             $spContainer->setSpId(($sheet->getParent()->getIndex($sheet) + 1) << 10);
@@ -270,7 +292,7 @@ class Xls extends BaseWriter implements IWriter
                 ++$countShapes[$sheetIndex];
 
                 // add the shape
-                $spContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer();
+                $spContainer = new SpContainer();
 
                 // set the shape type
                 $spContainer->setSpType(0x004B);
@@ -312,7 +334,7 @@ class Xls extends BaseWriter implements IWriter
 
             // AutoFilters
             if (!empty($filterRange)) {
-                $rangeBounds = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($filterRange);
+                $rangeBounds = Cell::rangeBoundaries($filterRange);
                 $iNumColStart = $rangeBounds[0][0];
                 $iNumColEnd = $rangeBounds[1][0];
 
@@ -321,14 +343,14 @@ class Xls extends BaseWriter implements IWriter
                     ++$countShapes[$sheetIndex];
 
                     // create an Drawing Object for the dropdown
-                    $oDrawing = new \PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing();
+                    $oDrawing = new BaseDrawing();
                     // get the coordinates of drawing
-                    $cDrawing = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($iInc - 1) . $rangeBounds[0][1];
+                    $cDrawing = Cell::stringFromColumnIndex($iInc - 1) . $rangeBounds[0][1];
                     $oDrawing->setCoordinates($cDrawing);
                     $oDrawing->setWorksheet($sheet);
 
                     // add the shape
-                    $spContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer();
+                    $spContainer = new SpContainer();
                     // set the shape type
                     $spContainer->setSpType(0x00C9);
                     // set the shape flag
@@ -352,7 +374,7 @@ class Xls extends BaseWriter implements IWriter
                     $spContainer->setOPT(0x03BF, 0x000A0000); // Group Shape -> fPrint
 
                     // set coordinates and offsets, client anchor
-                    $endCoordinates = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($iInc - 1);
+                    $endCoordinates = Cell::stringFromColumnIndex($iInc - 1);
                     $endCoordinates .= $rangeBounds[0][1] + 1;
 
                     $spContainer->setStartCoordinates($cDrawing);
@@ -400,10 +422,10 @@ class Xls extends BaseWriter implements IWriter
         }
 
         // if we reach here, then there are drawings in the workbook
-        $escher = new \PhpOffice\PhpSpreadsheet\Shared\Escher();
+        $escher = new Escher();
 
         // dggContainer
-        $dggContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer();
+        $dggContainer = new DggContainer();
         $escher->setDggContainer($dggContainer);
 
         // set IDCLs (identifier clusters)
@@ -435,40 +457,40 @@ class Xls extends BaseWriter implements IWriter
         $dggContainer->setCSpSaved($totalCountShapes + $countDrawings); // total number of shapes incl. one group shapes per drawing
 
         // bstoreContainer
-        $bstoreContainer = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer();
+        $bstoreContainer = new BstoreContainer();
         $dggContainer->setBstoreContainer($bstoreContainer);
 
         // the BSE's (all the images)
         foreach ($this->spreadsheet->getAllsheets() as $sheet) {
             foreach ($sheet->getDrawingCollection() as $drawing) {
                 if (!extension_loaded('gd')) {
-                    throw new \RuntimeException('Saving images in xls requires gd extension');
+                    throw new RuntimeException('Saving images in xls requires gd extension');
                 }
-                if ($drawing instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing) {
+                if ($drawing instanceof Drawing) {
                     $filename = $drawing->getPath();
 
                     list($imagesx, $imagesy, $imageFormat) = getimagesize($filename);
 
                     switch ($imageFormat) {
                         case 1: // GIF, not supported by BIFF8, we convert to PNG
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG;
+                            $blipType = BSE::BLIPTYPE_PNG;
                             ob_start();
                             imagepng(imagecreatefromgif($filename));
                             $blipData = ob_get_contents();
                             ob_end_clean();
                             break;
                         case 2: // JPEG
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_JPEG;
+                            $blipType = BSE::BLIPTYPE_JPEG;
                             $blipData = file_get_contents($filename);
                             break;
                         case 3: // PNG
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG;
+                            $blipType = BSE::BLIPTYPE_PNG;
                             $blipData = file_get_contents($filename);
                             break;
                         case 6: // Windows DIB (BMP), we convert to PNG
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG;
+                            $blipType = BSE::BLIPTYPE_PNG;
                             ob_start();
-                            imagepng(\PhpOffice\PhpSpreadsheet\Shared\Drawing::imagecreatefrombmp($filename));
+                            imagepng(SharedDrawing::imagecreatefrombmp($filename));
                             $blipData = ob_get_contents();
                             ob_end_clean();
                             break;
@@ -476,24 +498,24 @@ class Xls extends BaseWriter implements IWriter
                             continue 2;
                     }
 
-                    $blip = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip();
+                    $blip = new Blip();
                     $blip->setData($blipData);
 
-                    $BSE = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE();
+                    $BSE = new BSE();
                     $BSE->setBlipType($blipType);
                     $BSE->setBlip($blip);
 
                     $bstoreContainer->addBSE($BSE);
-                } elseif ($drawing instanceof \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing) {
+                } elseif ($drawing instanceof MemoryDrawing) {
                     switch ($drawing->getRenderingFunction()) {
-                        case \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_JPEG:
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_JPEG;
+                        case MemoryDrawing::RENDERING_JPEG:
+                            $blipType = BSE::BLIPTYPE_JPEG;
                             $renderingFunction = 'imagejpeg';
                             break;
-                        case \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_GIF:
-                        case \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_PNG:
-                        case \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing::RENDERING_DEFAULT:
-                            $blipType = \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG;
+                        case MemoryDrawing::RENDERING_GIF:
+                        case MemoryDrawing::RENDERING_PNG:
+                        case MemoryDrawing::RENDERING_DEFAULT:
+                            $blipType = BSE::BLIPTYPE_PNG;
                             $renderingFunction = 'imagepng';
                             break;
                     }
@@ -503,10 +525,10 @@ class Xls extends BaseWriter implements IWriter
                     $blipData = ob_get_contents();
                     ob_end_clean();
 
-                    $blip = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip();
+                    $blip = new Blip();
                     $blip->setData($blipData);
 
-                    $BSE = new \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE();
+                    $BSE = new BSE();
                     $BSE->setBlipType($blipType);
                     $BSE->setBlip($blip);
 
@@ -847,7 +869,7 @@ class Xls extends BaseWriter implements IWriter
                 'summary' => ['pack' => 'V', 'data' => 0x0C],
                 'offset' => ['pack' => 'V'],
                 'type' => ['pack' => 'V', 'data' => 0x40], // Filetime (64-bit value representing the number of 100-nanosecond intervals since January 1, 1601)
-                'data' => ['data' => \PhpOffice\PhpSpreadsheet\Shared\OLE::localDateToOLE($dataProp)],
+                'data' => ['data' => OLE::localDateToOLE($dataProp)],
             ];
             ++$dataSection_NumProps;
         }
@@ -858,7 +880,7 @@ class Xls extends BaseWriter implements IWriter
                 'summary' => ['pack' => 'V', 'data' => 0x0D],
                 'offset' => ['pack' => 'V'],
                 'type' => ['pack' => 'V', 'data' => 0x40], // Filetime (64-bit value representing the number of 100-nanosecond intervals since January 1, 1601)
-                'data' => ['data' => \PhpOffice\PhpSpreadsheet\Shared\OLE::localDateToOLE($dataProp)],
+                'data' => ['data' => OLE::localDateToOLE($dataProp)],
             ];
             ++$dataSection_NumProps;
         }
diff --git a/src/PhpSpreadsheet/Writer/Xls/BIFFwriter.php b/src/PhpSpreadsheet/Writer/Xls/BIFFwriter.php
index a45ba07b..e250254c 100644
--- a/src/PhpSpreadsheet/Writer/Xls/BIFFwriter.php
+++ b/src/PhpSpreadsheet/Writer/Xls/BIFFwriter.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -117,7 +119,7 @@ class BIFFwriter
                 $byte_order = 1; // Big Endian
             } else {
                 // Give up. I'll fix this in a later version.
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Required floating point format not supported on this platform.');
+                throw new WriterException('Required floating point format not supported on this platform.');
             }
             self::$byteOrder = $byte_order;
         }
diff --git a/src/PhpSpreadsheet/Writer/Xls/Escher.php b/src/PhpSpreadsheet/Writer/Xls/Escher.php
index 8926b192..adff2ae9 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Escher.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Escher.php
@@ -2,6 +2,15 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE;
+use PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -83,7 +92,7 @@ class Escher
                     $this->spTypes = $writer->getSpTypes();
                 }
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer::class:
+            case DggContainer::class:
                 // this is a container record
 
                 // initialize
@@ -136,7 +145,7 @@ class Escher
 
                 $this->data = $header . $innerData;
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer::class:
+            case BstoreContainer::class:
                 // this is a container record
 
                 // initialize
@@ -163,7 +172,7 @@ class Escher
 
                 $this->data = $header . $innerData;
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::class:
+            case BSE::class:
                 // this is a semi-container record
 
                 // initialize
@@ -212,12 +221,12 @@ class Escher
 
                 $this->data .= $data;
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE\Blip::class:
+            case Blip::class:
                 // this is an atom record
 
                 // write the record
                 switch ($this->object->getParent()->getBlipType()) {
-                    case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_JPEG:
+                    case BSE::BLIPTYPE_JPEG:
                         // initialize
                         $innerData = '';
 
@@ -243,7 +252,7 @@ class Escher
 
                         $this->data .= $innerData;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Shared\Escher\DggContainer\BstoreContainer\BSE::BLIPTYPE_PNG:
+                    case BSE::BLIPTYPE_PNG:
                         // initialize
                         $innerData = '';
 
@@ -271,7 +280,7 @@ class Escher
                         break;
                 }
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer::class:
+            case DgContainer::class:
                 // this is a container record
 
                 // initialize
@@ -323,7 +332,7 @@ class Escher
 
                 $this->data = $header . $innerData;
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer::class:
+            case SpgrContainer::class:
                 // this is a container record
 
                 // initialize
@@ -362,7 +371,7 @@ class Escher
                 $this->spOffsets = $spOffsets;
                 $this->spTypes = $spTypes;
                 break;
-            case \PhpOffice\PhpSpreadsheet\Shared\Escher\DgContainer\SpgrContainer\SpContainer::class:
+            case SpContainer::class:
                 // initialize
                 $data = '';
 
@@ -425,8 +434,8 @@ class Escher
                     $recType = 0xF010;
 
                     // start coordinates
-                    list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($this->object->getStartCoordinates());
-                    $c1 = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+                    list($column, $row) = Cell::coordinateFromString($this->object->getStartCoordinates());
+                    $c1 = Cell::columnIndexFromString($column) - 1;
                     $r1 = $row - 1;
 
                     // start offsetX
@@ -436,8 +445,8 @@ class Escher
                     $startOffsetY = $this->object->getStartOffsetY();
 
                     // end coordinates
-                    list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($this->object->getEndCoordinates());
-                    $c2 = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+                    list($column, $row) = Cell::coordinateFromString($this->object->getEndCoordinates());
+                    $c2 = Cell::columnIndexFromString($column) - 1;
                     $r2 = $row - 1;
 
                     // end offsetX
diff --git a/src/PhpSpreadsheet/Writer/Xls/Font.php b/src/PhpSpreadsheet/Writer/Xls/Font.php
index ba5c51bd..84b21981 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Font.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Font.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -114,7 +116,7 @@ class Font
             $bCharSet,
             $reserved
         );
-        $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeShort($this->font->getName());
+        $data .= StringHelper::UTF8toBIFF8UnicodeShort($this->font->getName());
 
         $length = strlen($data);
         $header = pack('vv', $record, $length);
diff --git a/src/PhpSpreadsheet/Writer/Xls/Parser.php b/src/PhpSpreadsheet/Writer/Xls/Parser.php
index dfa8bec5..f8243991 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Parser.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Parser.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -548,7 +551,7 @@ class Parser
         }
 
         // TODO: use real error codes
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown token $token");
+        throw new WriterException("Unknown token $token");
     }
 
     /**
@@ -583,10 +586,10 @@ class Parser
         // chop away beggining and ending quotes
         $string = substr($string, 1, strlen($string) - 2);
         if (strlen($string) > 255) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('String is too long');
+            throw new WriterException('String is too long');
         }
 
-        return pack('C', $this->ptg['ptgStr']) . \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeShort($string);
+        return pack('C', $this->ptg['ptgStr']) . StringHelper::UTF8toBIFF8UnicodeShort($string);
     }
 
     /**
@@ -626,7 +629,7 @@ class Parser
             list($cell1, $cell2) = explode(':', $range);
         } else {
             // TODO: use real error codes
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Unknown range separator');
+            throw new WriterException('Unknown range separator');
         }
 
         // Convert the cell references
@@ -642,7 +645,7 @@ class Parser
             $ptgArea = pack('C', $this->ptg['ptgAreaA']);
         } else {
             // TODO: use real error codes
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown class $class");
+            throw new WriterException("Unknown class $class");
         }
 
         return $ptgArea . $row1 . $row2 . $col1 . $col2;
@@ -773,11 +776,11 @@ class Parser
 
             $sheet1 = $this->getSheetIndex($sheet_name1);
             if ($sheet1 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $sheet_name1 in formula");
+                throw new WriterException("Unknown sheet name $sheet_name1 in formula");
             }
             $sheet2 = $this->getSheetIndex($sheet_name2);
             if ($sheet2 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $sheet_name2 in formula");
+                throw new WriterException("Unknown sheet name $sheet_name2 in formula");
             }
 
             // Reverse max and min sheet numbers if necessary
@@ -787,7 +790,7 @@ class Parser
         } else { // Single sheet name only.
             $sheet1 = $this->getSheetIndex($ext_ref);
             if ($sheet1 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $ext_ref in formula");
+                throw new WriterException("Unknown sheet name $ext_ref in formula");
             }
             $sheet2 = $sheet1;
         }
@@ -819,11 +822,11 @@ class Parser
 
             $sheet1 = $this->getSheetIndex($sheet_name1);
             if ($sheet1 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $sheet_name1 in formula");
+                throw new WriterException("Unknown sheet name $sheet_name1 in formula");
             }
             $sheet2 = $this->getSheetIndex($sheet_name2);
             if ($sheet2 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $sheet_name2 in formula");
+                throw new WriterException("Unknown sheet name $sheet_name2 in formula");
             }
 
             // Reverse max and min sheet numbers if necessary
@@ -833,7 +836,7 @@ class Parser
         } else { // Single sheet name only.
             $sheet1 = $this->getSheetIndex($ext_ref);
             if ($sheet1 == -1) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Unknown sheet name $ext_ref in formula");
+                throw new WriterException("Unknown sheet name $ext_ref in formula");
             }
             $sheet2 = $sheet1;
         }
@@ -903,10 +906,10 @@ class Parser
         $cell = strtoupper($cell);
         list($row, $col, $row_rel, $col_rel) = $this->cellToRowcol($cell);
         if ($col >= 256) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Column in: $cell greater than 255");
+            throw new WriterException("Column in: $cell greater than 255");
         }
         if ($row >= 65536) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Row in: $cell greater than 65536 ");
+            throw new WriterException("Row in: $cell greater than 65536 ");
         }
 
         // Set the high bits to indicate if row or col are relative.
@@ -944,7 +947,7 @@ class Parser
 
         // FIXME: this changes for BIFF8
         if (($row1 >= 65536) or ($row2 >= 65536)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Row in: $range greater than 65536 ");
+            throw new WriterException("Row in: $range greater than 65536 ");
         }
 
         // Set the high bits to indicate if rows are relative.
@@ -1307,7 +1310,7 @@ class Parser
             $this->advance(); // eat the "("
             $result = $this->parenthesizedExpression();
             if ($this->currentToken != ')') {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("')' token expected.");
+                throw new WriterException("')' token expected.");
             }
             $this->advance(); // eat the ")"
             return $result;
@@ -1369,7 +1372,7 @@ class Parser
 
             return $result;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Syntax error: ' . $this->currentToken . ', lookahead: ' . $this->lookAhead . ', current char: ' . $this->currentCharacter);
+        throw new WriterException('Syntax error: ' . $this->currentToken . ', lookahead: ' . $this->lookAhead . ', current char: ' . $this->currentCharacter);
     }
 
     /**
@@ -1390,7 +1393,7 @@ class Parser
                 if ($this->currentToken == ',' || $this->currentToken == ';') {
                     $this->advance(); // eat the "," or ";"
                 } else {
-                    throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Syntax error: comma expected in function $function, arg #{$num_args}");
+                    throw new WriterException("Syntax error: comma expected in function $function, arg #{$num_args}");
                 }
                 $result2 = $this->condition();
                 $result = $this->createTree('arg', $result, $result2);
@@ -1401,12 +1404,12 @@ class Parser
             ++$num_args;
         }
         if (!isset($this->functions[$function])) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Function $function() doesn't exist");
+            throw new WriterException("Function $function() doesn't exist");
         }
         $args = $this->functions[$function][1];
         // If fixed number of args eg. TIME($i, $j, $k). Check that the number of args is valid.
         if (($args >= 0) and ($args != $num_args)) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Incorrect number of arguments in function $function() ");
+            throw new WriterException("Incorrect number of arguments in function $function() ");
         }
 
         $result = $this->createTree($function, $result, $num_args);
diff --git a/src/PhpSpreadsheet/Writer/Xls/Workbook.php b/src/PhpSpreadsheet/Writer/Xls/Workbook.php
index 2f2056e1..a493a8bf 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Workbook.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Workbook.php
@@ -2,6 +2,12 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -108,14 +114,14 @@ class Workbook extends BIFFwriter
     /**
      * Workbook.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheet;
 
     /**
      * Fonts writers.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Writer\Xls\Font[]
+     * @var Font[]
      */
     private $fontWriters = [];
 
@@ -190,14 +196,14 @@ class Workbook extends BIFFwriter
     /**
      * Class constructor.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet The Workbook
+     * @param Spreadsheet $spreadsheet The Workbook
      * @param int $str_total Total number of strings
      * @param int $str_unique Total number of unique strings
      * @param array $str_table String Table
      * @param array $colors Colour Table
      * @param Parser $parser The formula parser created for the Workbook
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet, &$str_total, &$str_unique, &$str_table, &$colors, Parser $parser)
+    public function __construct(Spreadsheet $spreadsheet, &$str_total, &$str_unique, &$str_table, &$colors, Parser $parser)
     {
         // It needs to call its parent's constructor explicitly
         parent::__construct();
@@ -306,7 +312,7 @@ class Workbook extends BIFFwriter
             $countFonts = count($this->fontWriters);
             $fontIndex = ($countFonts < 4) ? $countFonts : $countFonts + 1;
 
-            $fontWriter = new \PhpOffice\PhpSpreadsheet\Writer\Xls\Font($font);
+            $fontWriter = new Font($font);
             $fontWriter->setColorIndex($this->addColor($font->getColor()->getRGB()));
             $this->fontWriters[] = $fontWriter;
 
@@ -484,7 +490,7 @@ class Workbook extends BIFFwriter
         // add size of Workbook globals part 2, the length of the SHEET records
         $total_worksheets = count($this->spreadsheet->getAllSheets());
         foreach ($this->spreadsheet->getWorksheetIterator() as $sheet) {
-            $offset += $boundsheet_length + strlen(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeShort($sheet->getTitle()));
+            $offset += $boundsheet_length + strlen(StringHelper::UTF8toBIFF8UnicodeShort($sheet->getTitle()));
         }
 
         // add the sizes of each of the Sheet substreams, respectively
@@ -563,15 +569,15 @@ class Workbook extends BIFFwriter
             // Write a Name record if the print area has been defined
             if ($sheetSetup->isPrintAreaSet()) {
                 // Print area
-                $printArea = \PhpOffice\PhpSpreadsheet\Cell::splitRange($sheetSetup->getPrintArea());
+                $printArea = Cell::splitRange($sheetSetup->getPrintArea());
                 $printArea = $printArea[0];
-                $printArea[0] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($printArea[0]);
-                $printArea[1] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($printArea[1]);
+                $printArea[0] = Cell::coordinateFromString($printArea[0]);
+                $printArea[1] = Cell::coordinateFromString($printArea[1]);
 
                 $print_rowmin = $printArea[0][1] - 1;
                 $print_rowmax = $printArea[1][1] - 1;
-                $print_colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($printArea[0][0]) - 1;
-                $print_colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($printArea[1][0]) - 1;
+                $print_colmin = Cell::columnIndexFromString($printArea[0][0]) - 1;
+                $print_colmax = Cell::columnIndexFromString($printArea[1][0]) - 1;
 
                 $this->writeNameShort(
                     $i, // sheet index
@@ -591,8 +597,8 @@ class Workbook extends BIFFwriter
             // simultaneous repeatColumns repeatRows
             if ($sheetSetup->isColumnsToRepeatAtLeftSet() && $sheetSetup->isRowsToRepeatAtTopSet()) {
                 $repeat = $sheetSetup->getColumnsToRepeatAtLeft();
-                $colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[0]) - 1;
-                $colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[1]) - 1;
+                $colmin = Cell::columnIndexFromString($repeat[0]) - 1;
+                $colmax = Cell::columnIndexFromString($repeat[1]) - 1;
 
                 $repeat = $sheetSetup->getRowsToRepeatAtTop();
                 $rowmin = $repeat[0] - 1;
@@ -612,8 +618,8 @@ class Workbook extends BIFFwriter
                 // Columns to repeat
                 if ($sheetSetup->isColumnsToRepeatAtLeftSet()) {
                     $repeat = $sheetSetup->getColumnsToRepeatAtLeft();
-                    $colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[0]) - 1;
-                    $colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[1]) - 1;
+                    $colmin = Cell::columnIndexFromString($repeat[0]) - 1;
+                    $colmax = Cell::columnIndexFromString($repeat[1]) - 1;
                 } else {
                     $colmin = 0;
                     $colmax = 255;
@@ -655,14 +661,14 @@ class Workbook extends BIFFwriter
             $namedRanges = $this->spreadsheet->getNamedRanges();
             foreach ($namedRanges as $namedRange) {
                 // Create absolute coordinate
-                $range = \PhpOffice\PhpSpreadsheet\Cell::splitRange($namedRange->getRange());
+                $range = Cell::splitRange($namedRange->getRange());
                 for ($i = 0; $i < count($range); ++$i) {
-                    $range[$i][0] = '\'' . str_replace("'", "''", $namedRange->getWorksheet()->getTitle()) . '\'!' . \PhpOffice\PhpSpreadsheet\Cell::absoluteCoordinate($range[$i][0]);
+                    $range[$i][0] = '\'' . str_replace("'", "''", $namedRange->getWorksheet()->getTitle()) . '\'!' . Cell::absoluteCoordinate($range[$i][0]);
                     if (isset($range[$i][1])) {
-                        $range[$i][1] = \PhpOffice\PhpSpreadsheet\Cell::absoluteCoordinate($range[$i][1]);
+                        $range[$i][1] = Cell::absoluteCoordinate($range[$i][1]);
                     }
                 }
-                $range = \PhpOffice\PhpSpreadsheet\Cell::buildRange($range); // e.g. Sheet1!$A$1:$B$2
+                $range = Cell::buildRange($range); // e.g. Sheet1!$A$1:$B$2
 
                 // parse formula
                 try {
@@ -682,7 +688,7 @@ class Workbook extends BIFFwriter
                         $scope = 0;
                     }
                     $chunk .= $this->writeData($this->writeDefinedNameBiff8($namedRange->getName(), $formulaData, $scope, false));
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     // do nothing
                 }
             }
@@ -697,8 +703,8 @@ class Workbook extends BIFFwriter
             // simultaneous repeatColumns repeatRows
             if ($sheetSetup->isColumnsToRepeatAtLeftSet() && $sheetSetup->isRowsToRepeatAtTopSet()) {
                 $repeat = $sheetSetup->getColumnsToRepeatAtLeft();
-                $colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[0]) - 1;
-                $colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[1]) - 1;
+                $colmin = Cell::columnIndexFromString($repeat[0]) - 1;
+                $colmax = Cell::columnIndexFromString($repeat[1]) - 1;
 
                 $repeat = $sheetSetup->getRowsToRepeatAtTop();
                 $rowmin = $repeat[0] - 1;
@@ -718,8 +724,8 @@ class Workbook extends BIFFwriter
                 // Columns to repeat
                 if ($sheetSetup->isColumnsToRepeatAtLeftSet()) {
                     $repeat = $sheetSetup->getColumnsToRepeatAtLeft();
-                    $colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[0]) - 1;
-                    $colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($repeat[1]) - 1;
+                    $colmin = Cell::columnIndexFromString($repeat[0]) - 1;
+                    $colmax = Cell::columnIndexFromString($repeat[1]) - 1;
                 } else {
                     $colmin = 0;
                     $colmax = 255;
@@ -747,19 +753,19 @@ class Workbook extends BIFFwriter
             $sheetSetup = $this->spreadsheet->getSheet($i)->getPageSetup();
             if ($sheetSetup->isPrintAreaSet()) {
                 // Print area, e.g. A3:J6,H1:X20
-                $printArea = \PhpOffice\PhpSpreadsheet\Cell::splitRange($sheetSetup->getPrintArea());
+                $printArea = Cell::splitRange($sheetSetup->getPrintArea());
                 $countPrintArea = count($printArea);
 
                 $formulaData = '';
                 for ($j = 0; $j < $countPrintArea; ++$j) {
                     $printAreaRect = $printArea[$j]; // e.g. A3:J6
-                    $printAreaRect[0] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($printAreaRect[0]);
-                    $printAreaRect[1] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($printAreaRect[1]);
+                    $printAreaRect[0] = Cell::coordinateFromString($printAreaRect[0]);
+                    $printAreaRect[1] = Cell::coordinateFromString($printAreaRect[1]);
 
                     $print_rowmin = $printAreaRect[0][1] - 1;
                     $print_rowmax = $printAreaRect[1][1] - 1;
-                    $print_colmin = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($printAreaRect[0][0]) - 1;
-                    $print_colmax = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($printAreaRect[1][0]) - 1;
+                    $print_colmin = Cell::columnIndexFromString($printAreaRect[0][0]) - 1;
+                    $print_colmax = Cell::columnIndexFromString($printAreaRect[1][0]) - 1;
 
                     // construct formula data manually because parser does not recognize absolute 3d cell references
                     $formulaData .= pack('Cvvvvv', 0x3B, $i, $print_rowmin, $print_rowmax, $print_colmin, $print_colmax);
@@ -779,7 +785,7 @@ class Workbook extends BIFFwriter
             $sheetAutoFilter = $this->spreadsheet->getSheet($i)->getAutoFilter();
             $autoFilterRange = $sheetAutoFilter->getRange();
             if (!empty($autoFilterRange)) {
-                $rangeBounds = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($autoFilterRange);
+                $rangeBounds = Cell::rangeBoundaries($autoFilterRange);
 
                 //Autofilter built in name
                 $name = pack('C', 0x0D);
@@ -809,10 +815,10 @@ class Workbook extends BIFFwriter
         $options = $isBuiltIn ? 0x20 : 0x00;
 
         // length of the name, character count
-        $nlen = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($name);
+        $nlen = StringHelper::countCharacters($name);
 
         // name with stripped length field
-        $name = substr(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($name), 2);
+        $name = substr(StringHelper::UTF8toBIFF8UnicodeLong($name), 2);
 
         // size of the formula (in bytes)
         $sz = strlen($formulaData);
@@ -944,7 +950,7 @@ class Workbook extends BIFFwriter
         $grbit = 0x0000; // Visibility and sheet type
 
         $data = pack('VCC', $offset, $ss, $st);
-        $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeShort($sheetname);
+        $data .= StringHelper::UTF8toBIFF8UnicodeShort($sheetname);
 
         $length = strlen($data);
         $header = pack('vv', $record, $length);
@@ -1012,7 +1018,7 @@ class Workbook extends BIFFwriter
     {
         $record = 0x041E; // Record identifier
 
-        $numberFormatString = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($format);
+        $numberFormatString = StringHelper::UTF8toBIFF8UnicodeLong($format);
         $length = 2 + strlen($numberFormatString); // Number of bytes to follow
 
         $header = pack('vv', $record, $length);
@@ -1028,7 +1034,7 @@ class Workbook extends BIFFwriter
         $record = 0x0022; // Record identifier
         $length = 0x0002; // Bytes to follow
 
-        $f1904 = (\PhpOffice\PhpSpreadsheet\Shared\Date::getExcelCalendar() == \PhpOffice\PhpSpreadsheet\Shared\Date::CALENDAR_MAC_1904)
+        $f1904 = (Date::getExcelCalendar() == Date::CALENDAR_MAC_1904)
             ? 1
             : 0; // Flag for 1904 date system
 
@@ -1416,7 +1422,7 @@ class Workbook extends BIFFwriter
     {
         // write the Escher stream if necessary
         if (isset($this->escher)) {
-            $writer = new \PhpOffice\PhpSpreadsheet\Writer\Xls\Escher($this->escher);
+            $writer = new Escher($this->escher);
             $data = $writer->close();
 
             $record = 0x00EB;
diff --git a/src/PhpSpreadsheet/Writer/Xls/Worksheet.php b/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
index 464df8c3..3e02af33 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Worksheet.php
@@ -2,6 +2,22 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Shared\Xls;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Conditional;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+use PhpOffice\PhpSpreadsheet\Worksheet\PageSetup;
+use PhpOffice\PhpSpreadsheet\Worksheet\SheetView;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -266,8 +282,8 @@ class Worksheet extends BIFFwriter
         // Determine lowest and highest column and row
         $this->lastRowIndex = ($maxR > 65535) ? 65535 : $maxR;
 
-        $this->firstColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($minC);
-        $this->lastColumnIndex = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($maxC);
+        $this->firstColumnIndex = Cell::columnIndexFromString($minC);
+        $this->lastColumnIndex = Cell::columnIndexFromString($maxC);
 
 //        if ($this->firstColumnIndex > 255) $this->firstColumnIndex = 255;
         if ($this->lastColumnIndex > 255) {
@@ -316,7 +332,7 @@ class Worksheet extends BIFFwriter
 
             $width = $defaultWidth;
 
-            $columnLetter = \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($i);
+            $columnLetter = Cell::stringFromColumnIndex($i);
             if (isset($columnDimensions[$columnLetter])) {
                 $columnDimension = $columnDimensions[$columnLetter];
                 if ($columnDimension->getWidth() >= 0) {
@@ -401,56 +417,56 @@ class Worksheet extends BIFFwriter
         foreach ($phpSheet->getCoordinates() as $coordinate) {
             $cell = $phpSheet->getCell($coordinate);
             $row = $cell->getRow() - 1;
-            $column = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($cell->getColumn()) - 1;
+            $column = Cell::columnIndexFromString($cell->getColumn()) - 1;
 
             // Don't break Excel break the code!
             if ($row > 65535 || $column > 255) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Rows or columns overflow! Excel5 has limit to 65535 rows and 255 columns. Use XLSX instead.');
+                throw new WriterException('Rows or columns overflow! Excel5 has limit to 65535 rows and 255 columns. Use XLSX instead.');
             }
 
             // Write cell value
             $xfIndex = $cell->getXfIndex() + 15; // there are 15 cell style Xfs
 
             $cVal = $cell->getValue();
-            if ($cVal instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+            if ($cVal instanceof RichText) {
                 $arrcRun = [];
-                $str_len = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($cVal->getPlainText(), 'UTF-8');
+                $str_len = StringHelper::countCharacters($cVal->getPlainText(), 'UTF-8');
                 $str_pos = 0;
                 $elements = $cVal->getRichTextElements();
                 foreach ($elements as $element) {
                     // FONT Index
-                    if ($element instanceof \PhpOffice\PhpSpreadsheet\RichText\Run) {
+                    if ($element instanceof RichText\Run) {
                         $str_fontidx = $this->fontHashIndex[$element->getFont()->getHashCode()];
                     } else {
                         $str_fontidx = 0;
                     }
                     $arrcRun[] = ['strlen' => $str_pos, 'fontidx' => $str_fontidx];
                     // Position FROM
-                    $str_pos += \PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($element->getText(), 'UTF-8');
+                    $str_pos += StringHelper::countCharacters($element->getText(), 'UTF-8');
                 }
                 $this->writeRichTextString($row, $column, $cVal->getPlainText(), $xfIndex, $arrcRun);
             } else {
                 switch ($cell->getDatatype()) {
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING:
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NULL:
+                    case Cell\DataType::TYPE_STRING:
+                    case Cell\DataType::TYPE_NULL:
                         if ($cVal === '' || $cVal === null) {
                             $this->writeBlank($row, $column, $xfIndex);
                         } else {
                             $this->writeString($row, $column, $cVal, $xfIndex);
                         }
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NUMERIC:
+                    case Cell\DataType::TYPE_NUMERIC:
                         $this->writeNumber($row, $column, $cVal, $xfIndex);
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_FORMULA:
+                    case Cell\DataType::TYPE_FORMULA:
                         $calculatedValue = $this->preCalculateFormulas ?
                             $cell->getCalculatedValue() : null;
                         $this->writeFormula($row, $column, $cVal, $xfIndex, $calculatedValue);
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_BOOL:
+                    case Cell\DataType::TYPE_BOOL:
                         $this->writeBoolErr($row, $column, $cVal, 0, $xfIndex);
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_ERROR:
+                    case Cell\DataType::TYPE_ERROR:
                         $this->writeBoolErr($row, $column, self::mapErrorCode($cVal), 1, $xfIndex);
                         break;
                 }
@@ -480,7 +496,7 @@ class Worksheet extends BIFFwriter
 
         // Hyperlinks
         foreach ($phpSheet->getHyperLinkCollection() as $coordinate => $hyperlink) {
-            list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($coordinate);
+            list($column, $row) = Cell::coordinateFromString($coordinate);
 
             $url = $hyperlink->getUrl();
 
@@ -494,7 +510,7 @@ class Worksheet extends BIFFwriter
                 $url = 'external:' . $url;
             }
 
-            $this->writeUrl($row - 1, \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1, $url);
+            $this->writeUrl($row - 1, Cell::columnIndexFromString($column) - 1, $url);
         }
 
         $this->writeDataValidity();
@@ -513,8 +529,8 @@ class Worksheet extends BIFFwriter
             // Write ConditionalFormattingTable records
             foreach ($arrConditionalStyles as $cellCoordinate => $conditionalStyles) {
                 foreach ($conditionalStyles as $conditional) {
-                    if ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_EXPRESSION
-                        || $conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS) {
+                    if ($conditional->getConditionType() == Conditional::CONDITION_EXPRESSION
+                        || $conditional->getConditionType() == Conditional::CONDITION_CELLIS) {
                         if (!isset($arrConditional[$conditional->getHashCode()])) {
                             // This hash code has been handled
                             $arrConditional[$conditional->getHashCode()] = true;
@@ -553,10 +569,10 @@ class Worksheet extends BIFFwriter
             $lastCell = $explodes[1];
         }
 
-        $firstCellCoordinates = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($firstCell); // e.g. array(0, 1)
-        $lastCellCoordinates = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($lastCell); // e.g. array(1, 6)
+        $firstCellCoordinates = Cell::coordinateFromString($firstCell); // e.g. array(0, 1)
+        $lastCellCoordinates = Cell::coordinateFromString($lastCell); // e.g. array(1, 6)
 
-        return pack('vvvv', $firstCellCoordinates[1] - 1, $lastCellCoordinates[1] - 1, \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($firstCellCoordinates[0]) - 1, \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($lastCellCoordinates[0]) - 1);
+        return pack('vvvv', $firstCellCoordinates[1] - 1, $lastCellCoordinates[1] - 1, Cell::columnIndexFromString($firstCellCoordinates[0]) - 1, Cell::columnIndexFromString($lastCellCoordinates[0]) - 1);
     }
 
     /**
@@ -671,7 +687,7 @@ class Worksheet extends BIFFwriter
     {
         $record = 0x00FD; // Record identifier
         $length = 0x000A; // Bytes to follow
-        $str = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeShort($str, $arrcRun);
+        $str = StringHelper::UTF8toBIFF8UnicodeShort($str, $arrcRun);
 
         /* check if string is already present */
         if (!isset($this->stringTable[$str])) {
@@ -741,7 +757,7 @@ class Worksheet extends BIFFwriter
         $record = 0x00FD; // Record identifier
         $length = 0x000A; // Bytes to follow
 
-        $str = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($str);
+        $str = StringHelper::UTF8toBIFF8UnicodeLong($str);
 
         /* check if string is already present */
         if (!isset($this->stringTable[$str])) {
@@ -869,7 +885,7 @@ class Worksheet extends BIFFwriter
                 // Numeric value
                 $num = pack('d', $calculatedValue);
             } elseif (is_string($calculatedValue)) {
-                $errorCodes = \PhpOffice\PhpSpreadsheet\Cell\DataType::getErrorCodes();
+                $errorCodes = Cell\DataType::getErrorCodes();
                 if (isset($errorCodes[$calculatedValue])) {
                     // Error value
                     $num = pack('CCCvCv', 0x02, 0x00, self::mapErrorCode($calculatedValue), 0x00, 0x00, 0xFFFF);
@@ -923,7 +939,7 @@ class Worksheet extends BIFFwriter
             }
 
             return 0;
-        } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+        } catch (PhpSpreadsheetException $e) {
             // do nothing
         }
     }
@@ -936,7 +952,7 @@ class Worksheet extends BIFFwriter
     private function writeStringRecord($stringValue)
     {
         $record = 0x0207; // Record identifier
-        $data = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($stringValue);
+        $data = StringHelper::UTF8toBIFF8UnicodeLong($stringValue);
 
         $length = strlen($data);
         $header = pack('vv', $record, $length);
@@ -1078,10 +1094,10 @@ class Worksheet extends BIFFwriter
         $url .= "\0";
 
         // character count
-        $url_len = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::countCharacters($url);
+        $url_len = StringHelper::countCharacters($url);
         $url_len = pack('V', $url_len);
 
-        $url = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::convertEncoding($url, 'UTF-16LE', 'UTF-8');
+        $url = StringHelper::convertEncoding($url, 'UTF-16LE', 'UTF-8');
 
         // Calculate the data length
         $length = 0x24 + strlen($url);
@@ -1293,7 +1309,7 @@ class Worksheet extends BIFFwriter
         // no support in PhpSpreadsheet for selected sheet, therefore sheet is only selected if it is the active sheet
         $fSelected = ($this->phpSheet === $this->phpSheet->getParent()->getActiveSheet()) ? 1 : 0;
         $fPaged = 1; // 2
-        $fPageBreakPreview = $this->phpSheet->getSheetView()->getView() === \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW;
+        $fPageBreakPreview = $this->phpSheet->getSheetView()->getView() === SheetView::SHEETVIEW_PAGE_BREAK_PREVIEW;
 
         $grbit = $fDspFmla;
         $grbit |= $fDspGrid << 1;
@@ -1423,7 +1439,7 @@ class Worksheet extends BIFFwriter
     {
         // look up the selected cell range
         $selectedCells = $this->phpSheet->getSelectedCells();
-        $selectedCells = \PhpOffice\PhpSpreadsheet\Cell::splitRange($this->phpSheet->getSelectedCells());
+        $selectedCells = Cell::splitRange($this->phpSheet->getSelectedCells());
         $selectedCells = $selectedCells[0];
         if (count($selectedCells) == 2) {
             list($first, $last) = $selectedCells;
@@ -1432,12 +1448,12 @@ class Worksheet extends BIFFwriter
             $last = $selectedCells[0];
         }
 
-        list($colFirst, $rwFirst) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($first);
-        $colFirst = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colFirst) - 1; // base 0 column index
+        list($colFirst, $rwFirst) = Cell::coordinateFromString($first);
+        $colFirst = Cell::columnIndexFromString($colFirst) - 1; // base 0 column index
         --$rwFirst; // base 0 row index
 
-        list($colLast, $rwLast) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($last);
-        $colLast = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colLast) - 1; // base 0 column index
+        list($colLast, $rwLast) = Cell::coordinateFromString($last);
+        $colLast = Cell::columnIndexFromString($colLast) - 1; // base 0 column index
         --$rwLast; // base 0 row index
 
         // make sure we are not out of bounds
@@ -1510,12 +1526,12 @@ class Worksheet extends BIFFwriter
             ++$j;
 
             // extract the row and column indexes
-            $range = \PhpOffice\PhpSpreadsheet\Cell::splitRange($mergeCell);
+            $range = Cell::splitRange($mergeCell);
             list($first, $last) = $range[0];
-            list($firstColumn, $firstRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($first);
-            list($lastColumn, $lastRow) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($last);
+            list($firstColumn, $firstRow) = Cell::coordinateFromString($first);
+            list($lastColumn, $lastRow) = Cell::coordinateFromString($last);
 
-            $recordData .= pack('vvvv', $firstRow - 1, $lastRow - 1, \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($firstColumn) - 1, \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($lastColumn) - 1);
+            $recordData .= pack('vvvv', $firstRow - 1, $lastRow - 1, Cell::columnIndexFromString($firstColumn) - 1, Cell::columnIndexFromString($lastColumn) - 1);
 
             // flush record if we have reached limit for number of merged cells, or reached final merged cell
             if ($j == $maxCountMergeCellsPerRecord or $i == $countMergeCells) {
@@ -1640,7 +1656,7 @@ class Worksheet extends BIFFwriter
                 hexdec($password)
             );
 
-            $recordData .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong('p' . md5($recordData));
+            $recordData .= StringHelper::UTF8toBIFF8UnicodeLong('p' . md5($recordData));
 
             $length = strlen($recordData);
 
@@ -1713,9 +1729,9 @@ class Worksheet extends BIFFwriter
     {
         $panes = [];
         if ($freezePane = $this->phpSheet->getFreezePane()) {
-            list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($freezePane);
+            list($column, $row) = Cell::coordinateFromString($freezePane);
             $panes[0] = $row - 1;
-            $panes[1] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column) - 1;
+            $panes[1] = Cell::columnIndexFromString($column) - 1;
         } else {
             // thaw panes
             return;
@@ -1813,7 +1829,7 @@ class Worksheet extends BIFFwriter
         $fLeftToRight = 0x0; // Print over then down
 
         // Page orientation
-        $fLandscape = ($this->phpSheet->getPageSetup()->getOrientation() == \PhpOffice\PhpSpreadsheet\Worksheet\PageSetup::ORIENTATION_LANDSCAPE) ?
+        $fLandscape = ($this->phpSheet->getPageSetup()->getOrientation() == PageSetup::ORIENTATION_LANDSCAPE) ?
             0x0 : 0x1;
 
         $fNoPls = 0x0; // Setup not read from printer
@@ -1862,7 +1878,7 @@ class Worksheet extends BIFFwriter
         }
         */
 
-        $recordData = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($this->phpSheet->getHeaderFooter()->getOddHeader());
+        $recordData = StringHelper::UTF8toBIFF8UnicodeLong($this->phpSheet->getHeaderFooter()->getOddHeader());
         $length = strlen($recordData);
 
         $header = pack('vv', $record, $length);
@@ -1886,7 +1902,7 @@ class Worksheet extends BIFFwriter
         }
         */
 
-        $recordData = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($this->phpSheet->getHeaderFooter()->getOddFooter());
+        $recordData = StringHelper::UTF8toBIFF8UnicodeLong($this->phpSheet->getHeaderFooter()->getOddFooter());
         $length = strlen($recordData);
 
         $header = pack('vv', $record, $length);
@@ -2056,7 +2072,7 @@ class Worksheet extends BIFFwriter
         $record = 0x009D; // Record identifier
         $length = 0x0002; // Bytes to follow
 
-        $rangeBounds = \PhpOffice\PhpSpreadsheet\Cell::rangeBoundaries($this->phpSheet->getAutoFilter()->getRange());
+        $rangeBounds = Cell::rangeBoundaries($this->phpSheet->getAutoFilter()->getRange());
         $iNumFilters = 1 + $rangeBounds[1][0] - $rangeBounds[0][0];
 
         $header = pack('vv', $record, $length);
@@ -2158,13 +2174,13 @@ class Worksheet extends BIFFwriter
 
         foreach ($this->phpSheet->getBreaks() as $cell => $breakType) {
             // Fetch coordinates
-            $coordinates = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($cell);
+            $coordinates = Cell::coordinateFromString($cell);
 
             // Decide what to do by the type of break
             switch ($breakType) {
                 case \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_COLUMN:
                     // Add to list of vertical breaks
-                    $vbreaks[] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($coordinates[0]) - 1;
+                    $vbreaks[] = Cell::columnIndexFromString($coordinates[0]) - 1;
                     break;
                 case \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_ROW:
                     // Add to list of horizontal breaks
@@ -2409,10 +2425,10 @@ class Worksheet extends BIFFwriter
         $row_end = $row_start; // Row containing bottom right corner of object
 
         // Zero the specified offset if greater than the cell dimensions
-        if ($x1 >= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start))) {
+        if ($x1 >= Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_start))) {
             $x1 = 0;
         }
-        if ($y1 >= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_start + 1)) {
+        if ($y1 >= Xls::sizeRow($this->phpSheet, $row_start + 1)) {
             $y1 = 0;
         }
 
@@ -2420,38 +2436,38 @@ class Worksheet extends BIFFwriter
         $height = $height + $y1 - 1;
 
         // Subtract the underlying cell widths to find the end cell of the image
-        while ($width >= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end))) {
-            $width -= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end));
+        while ($width >= Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_end))) {
+            $width -= Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_end));
             ++$col_end;
         }
 
         // Subtract the underlying cell heights to find the end cell of the image
-        while ($height >= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_end + 1)) {
-            $height -= \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_end + 1);
+        while ($height >= Xls::sizeRow($this->phpSheet, $row_end + 1)) {
+            $height -= Xls::sizeRow($this->phpSheet, $row_end + 1);
             ++$row_end;
         }
 
         // Bitmap isn't allowed to start or finish in a hidden cell, i.e. a cell
         // with zero eight or width.
         //
-        if (\PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start)) == 0) {
+        if (Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_start)) == 0) {
             return;
         }
-        if (\PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end)) == 0) {
+        if (Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_end)) == 0) {
             return;
         }
-        if (\PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_start + 1) == 0) {
+        if (Xls::sizeRow($this->phpSheet, $row_start + 1) == 0) {
             return;
         }
-        if (\PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_end + 1) == 0) {
+        if (Xls::sizeRow($this->phpSheet, $row_end + 1) == 0) {
             return;
         }
 
         // Convert the pixel values to the percentage value expected by Excel
-        $x1 = $x1 / \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_start)) * 1024;
-        $y1 = $y1 / \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_start + 1) * 256;
-        $x2 = $width / \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeCol($this->phpSheet, \PhpOffice\PhpSpreadsheet\Cell::stringFromColumnIndex($col_end)) * 1024; // Distance to right side of object
-        $y2 = $height / \PhpOffice\PhpSpreadsheet\Shared\Xls::sizeRow($this->phpSheet, $row_end + 1) * 256; // Distance to bottom of object
+        $x1 = $x1 / Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_start)) * 1024;
+        $y1 = $y1 / Xls::sizeRow($this->phpSheet, $row_start + 1) * 256;
+        $x2 = $width / Xls::sizeCol($this->phpSheet, Cell::stringFromColumnIndex($col_end)) * 1024; // Distance to right side of object
+        $y2 = $height / Xls::sizeRow($this->phpSheet, $row_end + 1) * 256; // Distance to bottom of object
 
         $this->writeObjPicture($col_start, $x1, $row_start, $y1, $col_end, $x2, $row_end, $y2);
     }
@@ -2577,7 +2593,7 @@ class Worksheet extends BIFFwriter
         // Open file.
         $bmp_fd = @fopen($bitmap, 'rb');
         if (!$bmp_fd) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Couldn't import $bitmap");
+            throw new WriterException("Couldn't import $bitmap");
         }
 
         // Slurp the file into a string.
@@ -2585,13 +2601,13 @@ class Worksheet extends BIFFwriter
 
         // Check that the file is big enough to be a bitmap.
         if (strlen($data) <= 0x36) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap doesn't contain enough data.\n");
+            throw new WriterException("$bitmap doesn't contain enough data.\n");
         }
 
         // The first 2 bytes are used to identify the bitmap.
         $identity = unpack('A2ident', $data);
         if ($identity['ident'] != 'BM') {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap doesn't appear to be a valid bitmap image.\n");
+            throw new WriterException("$bitmap doesn't appear to be a valid bitmap image.\n");
         }
 
         // Remove bitmap data: ID.
@@ -2615,20 +2631,20 @@ class Worksheet extends BIFFwriter
         $height = $width_and_height[2];
         $data = substr($data, 8);
         if ($width > 0xFFFF) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap: largest image width supported is 65k.\n");
+            throw new WriterException("$bitmap: largest image width supported is 65k.\n");
         }
         if ($height > 0xFFFF) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap: largest image height supported is 65k.\n");
+            throw new WriterException("$bitmap: largest image height supported is 65k.\n");
         }
 
         // Read and remove the bitmap planes and bpp data. Verify them.
         $planes_and_bitcount = unpack('v2', substr($data, 0, 4));
         $data = substr($data, 4);
         if ($planes_and_bitcount[2] != 24) { // Bitcount
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap isn't a 24bit true color bitmap.\n");
+            throw new WriterException("$bitmap isn't a 24bit true color bitmap.\n");
         }
         if ($planes_and_bitcount[1] != 1) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap: only 1 plane supported in bitmap image.\n");
+            throw new WriterException("$bitmap: only 1 plane supported in bitmap image.\n");
         }
 
         // Read and remove the bitmap compression. Verify compression.
@@ -2636,7 +2652,7 @@ class Worksheet extends BIFFwriter
         $data = substr($data, 4);
 
         if ($compression['comp'] != 0) {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("$bitmap: compression not supported in bitmap image.\n");
+            throw new WriterException("$bitmap: compression not supported in bitmap image.\n");
         }
 
         // Remove bitmap data: data size, hres, vres, colours, imp. colours.
@@ -2695,7 +2711,7 @@ class Worksheet extends BIFFwriter
     {
         // write the Escher stream if necessary
         if (isset($this->escher)) {
-            $writer = new \PhpOffice\PhpSpreadsheet\Writer\Xls\Escher($this->escher);
+            $writer = new Escher($this->escher);
             $data = $writer->close();
             $spOffsets = $writer->getSpOffsets();
             $spTypes = $writer->getSpTypes();
@@ -2809,28 +2825,28 @@ class Worksheet extends BIFFwriter
                 // data type
                 $type = $dataValidation->getType();
                 switch ($type) {
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_NONE:
+                    case DataValidation::TYPE_NONE:
                         $type = 0x00;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_WHOLE:
+                    case DataValidation::TYPE_WHOLE:
                         $type = 0x01;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_DECIMAL:
+                    case DataValidation::TYPE_DECIMAL:
                         $type = 0x02;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_LIST:
+                    case DataValidation::TYPE_LIST:
                         $type = 0x03;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_DATE:
+                    case DataValidation::TYPE_DATE:
                         $type = 0x04;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_TIME:
+                    case DataValidation::TYPE_TIME:
                         $type = 0x05;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_TEXTLENGTH:
+                    case DataValidation::TYPE_TEXTLENGTH:
                         $type = 0x06;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::TYPE_CUSTOM:
+                    case DataValidation::TYPE_CUSTOM:
                         $type = 0x07;
                         break;
                 }
@@ -2840,13 +2856,13 @@ class Worksheet extends BIFFwriter
                 // error style
                 $errorStyle = $dataValidation->getErrorStyle();
                 switch ($errorStyle) {
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_STOP:
+                    case DataValidation::STYLE_STOP:
                         $errorStyle = 0x00;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_WARNING:
+                    case DataValidation::STYLE_WARNING:
                         $errorStyle = 0x01;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::STYLE_INFORMATION:
+                    case DataValidation::STYLE_INFORMATION:
                         $errorStyle = 0x02;
                         break;
                 }
@@ -2873,28 +2889,28 @@ class Worksheet extends BIFFwriter
                 // condition operator
                 $operator = $dataValidation->getOperator();
                 switch ($operator) {
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_BETWEEN:
+                    case DataValidation::OPERATOR_BETWEEN:
                         $operator = 0x00;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_NOTBETWEEN:
+                    case DataValidation::OPERATOR_NOTBETWEEN:
                         $operator = 0x01;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_EQUAL:
+                    case DataValidation::OPERATOR_EQUAL:
                         $operator = 0x02;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_NOTEQUAL:
+                    case DataValidation::OPERATOR_NOTEQUAL:
                         $operator = 0x03;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_GREATERTHAN:
+                    case DataValidation::OPERATOR_GREATERTHAN:
                         $operator = 0x04;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_LESSTHAN:
+                    case DataValidation::OPERATOR_LESSTHAN:
                         $operator = 0x05;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_GREATERTHANOREQUAL:
+                    case DataValidation::OPERATOR_GREATERTHANOREQUAL:
                         $operator = 0x06;
                         break;
-                    case \PhpOffice\PhpSpreadsheet\Cell\DataValidation::OPERATOR_LESSTHANOREQUAL:
+                    case DataValidation::OPERATOR_LESSTHANOREQUAL:
                         $operator = 0x07;
                         break;
                 }
@@ -2906,22 +2922,22 @@ class Worksheet extends BIFFwriter
                 // prompt title
                 $promptTitle = $dataValidation->getPromptTitle() !== '' ?
                     $dataValidation->getPromptTitle() : chr(0);
-                $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($promptTitle);
+                $data .= StringHelper::UTF8toBIFF8UnicodeLong($promptTitle);
 
                 // error title
                 $errorTitle = $dataValidation->getErrorTitle() !== '' ?
                     $dataValidation->getErrorTitle() : chr(0);
-                $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($errorTitle);
+                $data .= StringHelper::UTF8toBIFF8UnicodeLong($errorTitle);
 
                 // prompt text
                 $prompt = $dataValidation->getPrompt() !== '' ?
                     $dataValidation->getPrompt() : chr(0);
-                $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($prompt);
+                $data .= StringHelper::UTF8toBIFF8UnicodeLong($prompt);
 
                 // error text
                 $error = $dataValidation->getError() !== '' ?
                     $dataValidation->getError() : chr(0);
-                $data .= \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($error);
+                $data .= StringHelper::UTF8toBIFF8UnicodeLong($error);
 
                 // formula 1
                 try {
@@ -2932,7 +2948,7 @@ class Worksheet extends BIFFwriter
                     $this->parser->parse($formula1);
                     $formula1 = $this->parser->toReversePolish();
                     $sz1 = strlen($formula1);
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     $sz1 = 0;
                     $formula1 = '';
                 }
@@ -2943,12 +2959,12 @@ class Worksheet extends BIFFwriter
                 try {
                     $formula2 = $dataValidation->getFormula2();
                     if ($formula2 === '') {
-                        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('No formula2');
+                        throw new WriterException('No formula2');
                     }
                     $this->parser->parse($formula2);
                     $formula2 = $this->parser->toReversePolish();
                     $sz2 = strlen($formula2);
-                } catch (\PhpOffice\PhpSpreadsheet\Exception $e) {
+                } catch (PhpSpreadsheetException $e) {
                     $sz2 = 0;
                     $formula2 = '';
                 }
@@ -3010,7 +3026,7 @@ class Worksheet extends BIFFwriter
         $wScalvePLV = $this->phpSheet->getSheetView()->getZoomScale(); // 2
 
         // The options flags that comprise $grbit
-        if ($this->phpSheet->getSheetView()->getView() == \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_PAGE_LAYOUT) {
+        if ($this->phpSheet->getSheetView()->getView() == SheetView::SHEETVIEW_PAGE_LAYOUT) {
             $fPageLayoutView = 1;
         } else {
             $fPageLayoutView = 0;
@@ -3030,43 +3046,43 @@ class Worksheet extends BIFFwriter
     /**
      * Write CFRule Record.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style\Conditional $conditional
+     * @param Conditional $conditional
      */
-    private function writeCFRule(\PhpOffice\PhpSpreadsheet\Style\Conditional $conditional)
+    private function writeCFRule(Conditional $conditional)
     {
         $record = 0x01B1; // Record identifier
 
         // $type : Type of the CF
         // $operatorType : Comparison operator
-        if ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_EXPRESSION) {
+        if ($conditional->getConditionType() == Conditional::CONDITION_EXPRESSION) {
             $type = 0x02;
             $operatorType = 0x00;
-        } elseif ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS) {
+        } elseif ($conditional->getConditionType() == Conditional::CONDITION_CELLIS) {
             $type = 0x01;
 
             switch ($conditional->getOperatorType()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_NONE:
+                case Conditional::OPERATOR_NONE:
                     $operatorType = 0x00;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_EQUAL:
+                case Conditional::OPERATOR_EQUAL:
                     $operatorType = 0x03;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_GREATERTHAN:
+                case Conditional::OPERATOR_GREATERTHAN:
                     $operatorType = 0x05;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_GREATERTHANOREQUAL:
+                case Conditional::OPERATOR_GREATERTHANOREQUAL:
                     $operatorType = 0x07;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_LESSTHAN:
+                case Conditional::OPERATOR_LESSTHAN:
                     $operatorType = 0x06;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_LESSTHANOREQUAL:
+                case Conditional::OPERATOR_LESSTHANOREQUAL:
                     $operatorType = 0x08;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_NOTEQUAL:
+                case Conditional::OPERATOR_NOTEQUAL:
                     $operatorType = 0x04;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_BETWEEN:
+                case Conditional::OPERATOR_BETWEEN:
                     $operatorType = 0x01;
                     break;
                     // not OPERATOR_NOTBETWEEN 0x02
@@ -3082,7 +3098,7 @@ class Worksheet extends BIFFwriter
             $szValue2 = 0x0000;
             $operand1 = pack('Cv', 0x1E, $arrConditions[0]);
             $operand2 = null;
-        } elseif ($numConditions == 2 && ($conditional->getOperatorType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_BETWEEN)) {
+        } elseif ($numConditions == 2 && ($conditional->getOperatorType() == Conditional::OPERATOR_BETWEEN)) {
             $szValue1 = ($arrConditions[0] <= 65535 ? 3 : 0x0000);
             $szValue2 = ($arrConditions[1] <= 65535 ? 3 : 0x0000);
             $operand1 = pack('Cv', 0x1E, $arrConditions[0]);
@@ -3116,14 +3132,14 @@ class Worksheet extends BIFFwriter
             $bFormatProt = 0;
         }
         // Border
-        $bBorderLeft = ($conditional->getStyle()->getBorders()->getLeft()->getColor()->getARGB() == \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK
-                        && $conditional->getStyle()->getBorders()->getLeft()->getBorderStyle() == \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE ? 1 : 0);
-        $bBorderRight = ($conditional->getStyle()->getBorders()->getRight()->getColor()->getARGB() == \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK
-                        && $conditional->getStyle()->getBorders()->getRight()->getBorderStyle() == \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE ? 1 : 0);
-        $bBorderTop = ($conditional->getStyle()->getBorders()->getTop()->getColor()->getARGB() == \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK
-                        && $conditional->getStyle()->getBorders()->getTop()->getBorderStyle() == \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE ? 1 : 0);
-        $bBorderBottom = ($conditional->getStyle()->getBorders()->getBottom()->getColor()->getARGB() == \PhpOffice\PhpSpreadsheet\Style\Color::COLOR_BLACK
-                        && $conditional->getStyle()->getBorders()->getBottom()->getBorderStyle() == \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE ? 1 : 0);
+        $bBorderLeft = ($conditional->getStyle()->getBorders()->getLeft()->getColor()->getARGB() == Color::COLOR_BLACK
+                        && $conditional->getStyle()->getBorders()->getLeft()->getBorderStyle() == Border::BORDER_NONE ? 1 : 0);
+        $bBorderRight = ($conditional->getStyle()->getBorders()->getRight()->getColor()->getARGB() == Color::COLOR_BLACK
+                        && $conditional->getStyle()->getBorders()->getRight()->getBorderStyle() == Border::BORDER_NONE ? 1 : 0);
+        $bBorderTop = ($conditional->getStyle()->getBorders()->getTop()->getColor()->getARGB() == Color::COLOR_BLACK
+                        && $conditional->getStyle()->getBorders()->getTop()->getBorderStyle() == Border::BORDER_NONE ? 1 : 0);
+        $bBorderBottom = ($conditional->getStyle()->getBorders()->getBottom()->getColor()->getARGB() == Color::COLOR_BLACK
+                        && $conditional->getStyle()->getBorders()->getBottom()->getBorderStyle() == Border::BORDER_NONE ? 1 : 0);
         if ($bBorderLeft == 0 || $bBorderRight == 0 || $bBorderTop == 0 || $bBorderBottom == 0) {
             $bFormatBorder = 1;
         } else {
@@ -3199,7 +3215,7 @@ class Worksheet extends BIFFwriter
                 $dataBlockFont = pack('VVVVVVVV', 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000);
                 $dataBlockFont .= pack('VVVVVVVV', 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000);
             } else {
-                $dataBlockFont = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::UTF8toBIFF8UnicodeLong($conditional->getStyle()->getFont()->getName());
+                $dataBlockFont = StringHelper::UTF8toBIFF8UnicodeLong($conditional->getStyle()->getFont()->getName());
             }
             // Font Size
             if ($conditional->getStyle()->getFont()->getSize() == null) {
@@ -3458,22 +3474,22 @@ class Worksheet extends BIFFwriter
             $blockAlign = 0;
             // Alignment and text break
             switch ($conditional->getStyle()->getAlignment()->getHorizontal()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL:
+                case Alignment::HORIZONTAL_GENERAL:
                     $blockAlign = 0;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT:
+                case Alignment::HORIZONTAL_LEFT:
                     $blockAlign = 1;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT:
+                case Alignment::HORIZONTAL_RIGHT:
                     $blockAlign = 3;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER:
+                case Alignment::HORIZONTAL_CENTER:
                     $blockAlign = 2;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS:
+                case Alignment::HORIZONTAL_CENTER_CONTINUOUS:
                     $blockAlign = 6;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY:
+                case Alignment::HORIZONTAL_JUSTIFY:
                     $blockAlign = 5;
                     break;
             }
@@ -3483,16 +3499,16 @@ class Worksheet extends BIFFwriter
                 $blockAlign |= 0 << 3;
             }
             switch ($conditional->getStyle()->getAlignment()->getVertical()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM:
+                case Alignment::VERTICAL_BOTTOM:
                     $blockAlign = 2 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP:
+                case Alignment::VERTICAL_TOP:
                     $blockAlign = 0 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER:
+                case Alignment::VERTICAL_CENTER:
                     $blockAlign = 1 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY:
+                case Alignment::VERTICAL_JUSTIFY:
                     $blockAlign = 3 << 4;
                     break;
             }
@@ -3518,178 +3534,178 @@ class Worksheet extends BIFFwriter
         if ($bFormatBorder == 1) {
             $blockLineStyle = 0;
             switch ($conditional->getStyle()->getBorders()->getLeft()->getBorderStyle()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+                case Border::BORDER_NONE:
                     $blockLineStyle |= 0x00;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+                case Border::BORDER_THIN:
                     $blockLineStyle |= 0x01;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+                case Border::BORDER_MEDIUM:
                     $blockLineStyle |= 0x02;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+                case Border::BORDER_DASHED:
                     $blockLineStyle |= 0x03;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+                case Border::BORDER_DOTTED:
                     $blockLineStyle |= 0x04;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+                case Border::BORDER_THICK:
                     $blockLineStyle |= 0x05;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+                case Border::BORDER_DOUBLE:
                     $blockLineStyle |= 0x06;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+                case Border::BORDER_HAIR:
                     $blockLineStyle |= 0x07;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+                case Border::BORDER_MEDIUMDASHED:
                     $blockLineStyle |= 0x08;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+                case Border::BORDER_DASHDOT:
                     $blockLineStyle |= 0x09;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+                case Border::BORDER_MEDIUMDASHDOT:
                     $blockLineStyle |= 0x0A;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+                case Border::BORDER_DASHDOTDOT:
                     $blockLineStyle |= 0x0B;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+                case Border::BORDER_MEDIUMDASHDOTDOT:
                     $blockLineStyle |= 0x0C;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+                case Border::BORDER_SLANTDASHDOT:
                     $blockLineStyle |= 0x0D;
                     break;
             }
             switch ($conditional->getStyle()->getBorders()->getRight()->getBorderStyle()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+                case Border::BORDER_NONE:
                     $blockLineStyle |= 0x00 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+                case Border::BORDER_THIN:
                     $blockLineStyle |= 0x01 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+                case Border::BORDER_MEDIUM:
                     $blockLineStyle |= 0x02 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+                case Border::BORDER_DASHED:
                     $blockLineStyle |= 0x03 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+                case Border::BORDER_DOTTED:
                     $blockLineStyle |= 0x04 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+                case Border::BORDER_THICK:
                     $blockLineStyle |= 0x05 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+                case Border::BORDER_DOUBLE:
                     $blockLineStyle |= 0x06 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+                case Border::BORDER_HAIR:
                     $blockLineStyle |= 0x07 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+                case Border::BORDER_MEDIUMDASHED:
                     $blockLineStyle |= 0x08 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+                case Border::BORDER_DASHDOT:
                     $blockLineStyle |= 0x09 << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+                case Border::BORDER_MEDIUMDASHDOT:
                     $blockLineStyle |= 0x0A << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+                case Border::BORDER_DASHDOTDOT:
                     $blockLineStyle |= 0x0B << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+                case Border::BORDER_MEDIUMDASHDOTDOT:
                     $blockLineStyle |= 0x0C << 4;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+                case Border::BORDER_SLANTDASHDOT:
                     $blockLineStyle |= 0x0D << 4;
                     break;
             }
             switch ($conditional->getStyle()->getBorders()->getTop()->getBorderStyle()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+                case Border::BORDER_NONE:
                     $blockLineStyle |= 0x00 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+                case Border::BORDER_THIN:
                     $blockLineStyle |= 0x01 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+                case Border::BORDER_MEDIUM:
                     $blockLineStyle |= 0x02 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+                case Border::BORDER_DASHED:
                     $blockLineStyle |= 0x03 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+                case Border::BORDER_DOTTED:
                     $blockLineStyle |= 0x04 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+                case Border::BORDER_THICK:
                     $blockLineStyle |= 0x05 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+                case Border::BORDER_DOUBLE:
                     $blockLineStyle |= 0x06 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+                case Border::BORDER_HAIR:
                     $blockLineStyle |= 0x07 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+                case Border::BORDER_MEDIUMDASHED:
                     $blockLineStyle |= 0x08 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+                case Border::BORDER_DASHDOT:
                     $blockLineStyle |= 0x09 << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+                case Border::BORDER_MEDIUMDASHDOT:
                     $blockLineStyle |= 0x0A << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+                case Border::BORDER_DASHDOTDOT:
                     $blockLineStyle |= 0x0B << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+                case Border::BORDER_MEDIUMDASHDOTDOT:
                     $blockLineStyle |= 0x0C << 8;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+                case Border::BORDER_SLANTDASHDOT:
                     $blockLineStyle |= 0x0D << 8;
                     break;
             }
             switch ($conditional->getStyle()->getBorders()->getBottom()->getBorderStyle()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+                case Border::BORDER_NONE:
                     $blockLineStyle |= 0x00 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+                case Border::BORDER_THIN:
                     $blockLineStyle |= 0x01 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+                case Border::BORDER_MEDIUM:
                     $blockLineStyle |= 0x02 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+                case Border::BORDER_DASHED:
                     $blockLineStyle |= 0x03 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+                case Border::BORDER_DOTTED:
                     $blockLineStyle |= 0x04 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+                case Border::BORDER_THICK:
                     $blockLineStyle |= 0x05 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+                case Border::BORDER_DOUBLE:
                     $blockLineStyle |= 0x06 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+                case Border::BORDER_HAIR:
                     $blockLineStyle |= 0x07 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+                case Border::BORDER_MEDIUMDASHED:
                     $blockLineStyle |= 0x08 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+                case Border::BORDER_DASHDOT:
                     $blockLineStyle |= 0x09 << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+                case Border::BORDER_MEDIUMDASHDOT:
                     $blockLineStyle |= 0x0A << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+                case Border::BORDER_DASHDOTDOT:
                     $blockLineStyle |= 0x0B << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+                case Border::BORDER_MEDIUMDASHDOTDOT:
                     $blockLineStyle |= 0x0C << 12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+                case Border::BORDER_SLANTDASHDOT:
                     $blockLineStyle |= 0x0D << 12;
                     break;
             }
@@ -3702,46 +3718,46 @@ class Worksheet extends BIFFwriter
             //@todo writeCFRule() => $blockColor => Index Color for bottom line
             //@todo writeCFRule() => $blockColor => Index Color for diagonal line
             switch ($conditional->getStyle()->getBorders()->getDiagonal()->getBorderStyle()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE:
+                case Border::BORDER_NONE:
                     $blockColor |= 0x00 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN:
+                case Border::BORDER_THIN:
                     $blockColor |= 0x01 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM:
+                case Border::BORDER_MEDIUM:
                     $blockColor |= 0x02 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED:
+                case Border::BORDER_DASHED:
                     $blockColor |= 0x03 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED:
+                case Border::BORDER_DOTTED:
                     $blockColor |= 0x04 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK:
+                case Border::BORDER_THICK:
                     $blockColor |= 0x05 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE:
+                case Border::BORDER_DOUBLE:
                     $blockColor |= 0x06 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR:
+                case Border::BORDER_HAIR:
                     $blockColor |= 0x07 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED:
+                case Border::BORDER_MEDIUMDASHED:
                     $blockColor |= 0x08 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT:
+                case Border::BORDER_DASHDOT:
                     $blockColor |= 0x09 << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT:
+                case Border::BORDER_MEDIUMDASHDOT:
                     $blockColor |= 0x0A << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT:
+                case Border::BORDER_DASHDOTDOT:
                     $blockColor |= 0x0B << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT:
+                case Border::BORDER_MEDIUMDASHDOTDOT:
                     $blockColor |= 0x0C << 21;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT:
+                case Border::BORDER_SLANTDASHDOT:
                     $blockColor |= 0x0D << 21;
                     break;
             }
@@ -3751,67 +3767,67 @@ class Worksheet extends BIFFwriter
             // Fill Patern Style
             $blockFillPatternStyle = 0;
             switch ($conditional->getStyle()->getFill()->getFillType()) {
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE:
+                case Fill::FILL_NONE:
                     $blockFillPatternStyle = 0x00;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID:
+                case Fill::FILL_SOLID:
                     $blockFillPatternStyle = 0x01;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_MEDIUMGRAY:
+                case Fill::FILL_PATTERN_MEDIUMGRAY:
                     $blockFillPatternStyle = 0x02;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRAY:
+                case Fill::FILL_PATTERN_DARKGRAY:
                     $blockFillPatternStyle = 0x03;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRAY:
+                case Fill::FILL_PATTERN_LIGHTGRAY:
                     $blockFillPatternStyle = 0x04;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKHORIZONTAL:
+                case Fill::FILL_PATTERN_DARKHORIZONTAL:
                     $blockFillPatternStyle = 0x05;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKVERTICAL:
+                case Fill::FILL_PATTERN_DARKVERTICAL:
                     $blockFillPatternStyle = 0x06;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKDOWN:
+                case Fill::FILL_PATTERN_DARKDOWN:
                     $blockFillPatternStyle = 0x07;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKUP:
+                case Fill::FILL_PATTERN_DARKUP:
                     $blockFillPatternStyle = 0x08;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRID:
+                case Fill::FILL_PATTERN_DARKGRID:
                     $blockFillPatternStyle = 0x09;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKTRELLIS:
+                case Fill::FILL_PATTERN_DARKTRELLIS:
                     $blockFillPatternStyle = 0x0A;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTHORIZONTAL:
+                case Fill::FILL_PATTERN_LIGHTHORIZONTAL:
                     $blockFillPatternStyle = 0x0B;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTVERTICAL:
+                case Fill::FILL_PATTERN_LIGHTVERTICAL:
                     $blockFillPatternStyle = 0x0C;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTDOWN:
+                case Fill::FILL_PATTERN_LIGHTDOWN:
                     $blockFillPatternStyle = 0x0D;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTUP:
+                case Fill::FILL_PATTERN_LIGHTUP:
                     $blockFillPatternStyle = 0x0E;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRID:
+                case Fill::FILL_PATTERN_LIGHTGRID:
                     $blockFillPatternStyle = 0x0F;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTTRELLIS:
+                case Fill::FILL_PATTERN_LIGHTTRELLIS:
                     $blockFillPatternStyle = 0x10;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY125:
+                case Fill::FILL_PATTERN_GRAY125:
                     $blockFillPatternStyle = 0x11;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY0625:
+                case Fill::FILL_PATTERN_GRAY0625:
                     $blockFillPatternStyle = 0x12;
                     break;
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR:
+                case Fill::FILL_GRADIENT_LINEAR:
                     $blockFillPatternStyle = 0x00;
                     break; // does not exist in BIFF8
-                case \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_PATH:
+                case Fill::FILL_GRADIENT_PATH:
                     $blockFillPatternStyle = 0x00;
                     break; // does not exist in BIFF8
                 default:
@@ -4171,10 +4187,10 @@ class Worksheet extends BIFFwriter
         }
         if ($bFormatProt == 1) {
             $dataBlockProtection = 0;
-            if ($conditional->getStyle()->getProtection()->getLocked() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED) {
+            if ($conditional->getStyle()->getProtection()->getLocked() == Protection::PROTECTION_PROTECTED) {
                 $dataBlockProtection = 1;
             }
-            if ($conditional->getStyle()->getProtection()->getHidden() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED) {
+            if ($conditional->getStyle()->getProtection()->getHidden() == Protection::PROTECTION_PROTECTED) {
                 $dataBlockProtection = 1 << 1;
             }
         }
@@ -4220,15 +4236,15 @@ class Worksheet extends BIFFwriter
         $arrConditional = [];
         foreach ($this->phpSheet->getConditionalStylesCollection() as $cellCoordinate => $conditionalStyles) {
             foreach ($conditionalStyles as $conditional) {
-                if ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_EXPRESSION
-                        || $conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS) {
+                if ($conditional->getConditionType() == Conditional::CONDITION_EXPRESSION
+                        || $conditional->getConditionType() == Conditional::CONDITION_CELLIS) {
                     if (!in_array($conditional->getHashCode(), $arrConditional)) {
                         $arrConditional[] = $conditional->getHashCode();
                     }
                     // Cells
-                    $arrCoord = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($cellCoordinate);
+                    $arrCoord = Cell::coordinateFromString($cellCoordinate);
                     if (!is_numeric($arrCoord[0])) {
-                        $arrCoord[0] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($arrCoord[0]);
+                        $arrCoord[0] = Cell::columnIndexFromString($arrCoord[0]);
                     }
                     if (is_null($numColumnMin) || ($numColumnMin > $arrCoord[0])) {
                         $numColumnMin = $arrCoord[0];
diff --git a/src/PhpSpreadsheet/Writer/Xls/Xf.php b/src/PhpSpreadsheet/Writer/Xls/Xf.php
index 23f76f6a..8b911cb7 100644
--- a/src/PhpSpreadsheet/Writer/Xls/Xf.php
+++ b/src/PhpSpreadsheet/Writer/Xls/Xf.php
@@ -2,6 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xls;
 
+use PhpOffice\PhpSpreadsheet\Style;
+use PhpOffice\PhpSpreadsheet\Style\Alignment;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Borders;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -134,9 +141,9 @@ class Xf
     /**
      * Constructor.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Style The XF format
+     * @param Style The XF format
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Style $style)
+    public function __construct(Style $style)
     {
         $this->isStyleXf = false;
         $this->fontIndex = 0;
@@ -233,10 +240,10 @@ class Xf
         $border1 |= $this->rightBorderColor << 23;
 
         $diagonalDirection = $this->_style->getBorders()->getDiagonalDirection();
-        $diag_tl_to_rb = $diagonalDirection == \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_BOTH
-                            || $diagonalDirection == \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_DOWN;
-        $diag_tr_to_lb = $diagonalDirection == \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_BOTH
-                            || $diagonalDirection == \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_UP;
+        $diag_tl_to_rb = $diagonalDirection == Borders::DIAGONAL_BOTH
+                            || $diagonalDirection == Borders::DIAGONAL_DOWN;
+        $diag_tr_to_lb = $diagonalDirection == Borders::DIAGONAL_BOTH
+                            || $diagonalDirection == Borders::DIAGONAL_UP;
         $border1 |= $diag_tl_to_rb << 30;
         $border1 |= $diag_tr_to_lb << 31;
 
@@ -366,20 +373,20 @@ class Xf
      * @static    array of int
      */
     private static $mapBorderStyles = [
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE => 0x00,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THIN => 0x01,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUM => 0x02,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHED => 0x03,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOTTED => 0x04,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_THICK => 0x05,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DOUBLE => 0x06,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_HAIR => 0x07,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHED => 0x08,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOT => 0x09,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOT => 0x0A,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_DASHDOTDOT => 0x0B,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_MEDIUMDASHDOTDOT => 0x0C,
-        \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_SLANTDASHDOT => 0x0D,
+        Border::BORDER_NONE => 0x00,
+        Border::BORDER_THIN => 0x01,
+        Border::BORDER_MEDIUM => 0x02,
+        Border::BORDER_DASHED => 0x03,
+        Border::BORDER_DOTTED => 0x04,
+        Border::BORDER_THICK => 0x05,
+        Border::BORDER_DOUBLE => 0x06,
+        Border::BORDER_HAIR => 0x07,
+        Border::BORDER_MEDIUMDASHED => 0x08,
+        Border::BORDER_DASHDOT => 0x09,
+        Border::BORDER_MEDIUMDASHDOT => 0x0A,
+        Border::BORDER_DASHDOTDOT => 0x0B,
+        Border::BORDER_MEDIUMDASHDOTDOT => 0x0C,
+        Border::BORDER_SLANTDASHDOT => 0x0D,
     ];
 
     /**
@@ -404,27 +411,27 @@ class Xf
      * @static    array of int
      */
     private static $mapFillTypes = [
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE => 0x00,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_SOLID => 0x01,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_MEDIUMGRAY => 0x02,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRAY => 0x03,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRAY => 0x04,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKHORIZONTAL => 0x05,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKVERTICAL => 0x06,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKDOWN => 0x07,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKUP => 0x08,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKGRID => 0x09,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_DARKTRELLIS => 0x0A,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTHORIZONTAL => 0x0B,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTVERTICAL => 0x0C,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTDOWN => 0x0D,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTUP => 0x0E,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTGRID => 0x0F,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_LIGHTTRELLIS => 0x10,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY125 => 0x11,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY0625 => 0x12,
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR => 0x00, // does not exist in BIFF8
-        \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_PATH => 0x00, // does not exist in BIFF8
+        Fill::FILL_NONE => 0x00,
+        Fill::FILL_SOLID => 0x01,
+        Fill::FILL_PATTERN_MEDIUMGRAY => 0x02,
+        Fill::FILL_PATTERN_DARKGRAY => 0x03,
+        Fill::FILL_PATTERN_LIGHTGRAY => 0x04,
+        Fill::FILL_PATTERN_DARKHORIZONTAL => 0x05,
+        Fill::FILL_PATTERN_DARKVERTICAL => 0x06,
+        Fill::FILL_PATTERN_DARKDOWN => 0x07,
+        Fill::FILL_PATTERN_DARKUP => 0x08,
+        Fill::FILL_PATTERN_DARKGRID => 0x09,
+        Fill::FILL_PATTERN_DARKTRELLIS => 0x0A,
+        Fill::FILL_PATTERN_LIGHTHORIZONTAL => 0x0B,
+        Fill::FILL_PATTERN_LIGHTVERTICAL => 0x0C,
+        Fill::FILL_PATTERN_LIGHTDOWN => 0x0D,
+        Fill::FILL_PATTERN_LIGHTUP => 0x0E,
+        Fill::FILL_PATTERN_LIGHTGRID => 0x0F,
+        Fill::FILL_PATTERN_LIGHTTRELLIS => 0x10,
+        Fill::FILL_PATTERN_GRAY125 => 0x11,
+        Fill::FILL_PATTERN_GRAY0625 => 0x12,
+        Fill::FILL_GRADIENT_LINEAR => 0x00, // does not exist in BIFF8
+        Fill::FILL_GRADIENT_PATH => 0x00, // does not exist in BIFF8
     ];
 
     /**
@@ -449,13 +456,13 @@ class Xf
      * @static    array of int
      */
     private static $mapHAlignments = [
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_GENERAL => 0,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_LEFT => 1,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER => 2,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_RIGHT => 3,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_FILL => 4,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_JUSTIFY => 5,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::HORIZONTAL_CENTER_CONTINUOUS => 6,
+        Alignment::HORIZONTAL_GENERAL => 0,
+        Alignment::HORIZONTAL_LEFT => 1,
+        Alignment::HORIZONTAL_CENTER => 2,
+        Alignment::HORIZONTAL_RIGHT => 3,
+        Alignment::HORIZONTAL_FILL => 4,
+        Alignment::HORIZONTAL_JUSTIFY => 5,
+        Alignment::HORIZONTAL_CENTER_CONTINUOUS => 6,
     ];
 
     /**
@@ -480,10 +487,10 @@ class Xf
      * @static    array of int
      */
     private static $mapVAlignments = [
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_TOP => 0,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_CENTER => 1,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_BOTTOM => 2,
-        \PhpOffice\PhpSpreadsheet\Style\Alignment::VERTICAL_JUSTIFY => 3,
+        Alignment::VERTICAL_TOP => 0,
+        Alignment::VERTICAL_CENTER => 1,
+        Alignment::VERTICAL_BOTTOM => 2,
+        Alignment::VERTICAL_JUSTIFY => 3,
     ];
 
     /**
@@ -531,11 +538,11 @@ class Xf
     private static function mapLocked($locked)
     {
         switch ($locked) {
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT:
+            case Protection::PROTECTION_INHERIT:
                 return 1;
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED:
+            case Protection::PROTECTION_PROTECTED:
                 return 1;
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED:
+            case Protection::PROTECTION_UNPROTECTED:
                 return 0;
             default:
                 return 1;
@@ -553,11 +560,11 @@ class Xf
     private static function mapHidden($hidden)
     {
         switch ($hidden) {
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT:
+            case Protection::PROTECTION_INHERIT:
                 return 0;
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED:
+            case Protection::PROTECTION_PROTECTED:
                 return 1;
-            case \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_UNPROTECTED:
+            case Protection::PROTECTION_UNPROTECTED:
                 return 0;
             default:
                 return 0;
diff --git a/src/PhpSpreadsheet/Writer/Xlsx.php b/src/PhpSpreadsheet/Writer/Xlsx.php
index 56f1c508..93ea21db 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx.php
@@ -2,7 +2,27 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer;
 
+use PhpOffice\PhpSpreadsheet\Calculation;
+use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheet\HashTable;
+use PhpOffice\PhpSpreadsheet\Shared\File;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\Drawing as WorksheetDrawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Chart;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Comments;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\ContentTypes;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\DocProps;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Drawing;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Rels;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\RelsRibbon;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\RelsVBA;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\StringTable;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Style;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Theme;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Workbook;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx\Worksheet;
 use ZipArchive;
 
 /**
@@ -46,7 +66,7 @@ class Xlsx extends BaseWriter implements IWriter
     /**
      * Private Spreadsheet.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadSheet;
 
@@ -58,78 +78,78 @@ class Xlsx extends BaseWriter implements IWriter
     private $stringTable = [];
 
     /**
-     * Private unique \PhpOffice\PhpSpreadsheet\Style\Conditional HashTable.
+     * Private unique Conditional HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $stylesConditionalHashTable;
 
     /**
-     * Private unique \PhpOffice\PhpSpreadsheet\Style HashTable.
+     * Private unique Style HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $styleHashTable;
 
     /**
-     * Private unique \PhpOffice\PhpSpreadsheet\Style\Fill HashTable.
+     * Private unique Fill HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $fillHashTable;
 
     /**
      * Private unique \PhpOffice\PhpSpreadsheet\Style\Font HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $fontHashTable;
 
     /**
-     * Private unique \PhpOffice\PhpSpreadsheet\Style\Borders HashTable.
+     * Private unique Borders HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $bordersHashTable;
 
     /**
-     * Private unique \PhpOffice\PhpSpreadsheet\Style\NumberFormat HashTable.
+     * Private unique NumberFormat HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $numFmtHashTable;
 
     /**
      * Private unique \PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing HashTable.
      *
-     * @var \PhpOffice\PhpSpreadsheet\HashTable
+     * @var HashTable
      */
     private $drawingHashTable;
 
     /**
      * Create a new Xlsx Writer.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet)
+    public function __construct(Spreadsheet $spreadsheet)
     {
         // Assign PhpSpreadsheet
         $this->setSpreadsheet($spreadsheet);
 
         $writerPartsArray = [
-            'stringtable' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\StringTable::class,
-            'contenttypes' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\ContentTypes::class,
-            'docprops' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\DocProps::class,
-            'rels' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Rels::class,
-            'theme' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Theme::class,
-            'style' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Style::class,
-            'workbook' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Workbook::class,
-            'worksheet' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Worksheet::class,
-            'drawing' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Drawing::class,
-            'comments' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Comments::class,
-            'chart' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\Chart::class,
-            'relsvba' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\RelsVBA::class,
-            'relsribbonobjects' => \PhpOffice\PhpSpreadsheet\Writer\Xlsx\RelsRibbon::class,
+            'stringtable' => StringTable::class,
+            'contenttypes' => ContentTypes::class,
+            'docprops' => DocProps::class,
+            'rels' => Rels::class,
+            'theme' => Theme::class,
+            'style' => Style::class,
+            'workbook' => Workbook::class,
+            'worksheet' => Worksheet::class,
+            'drawing' => Drawing::class,
+            'comments' => Comments::class,
+            'chart' => Chart::class,
+            'relsvba' => RelsVBA::class,
+            'relsribbonobjects' => RelsRibbon::class,
         ];
 
         //    Initialise writer parts
@@ -145,7 +165,7 @@ class Xlsx extends BaseWriter implements IWriter
 
         // Set HashTable variables
         foreach ($hashTablesArray as $tableName) {
-            $this->$tableName = new \PhpOffice\PhpSpreadsheet\HashTable();
+            $this->$tableName = new HashTable();
         }
     }
 
@@ -170,7 +190,7 @@ class Xlsx extends BaseWriter implements IWriter
      *
      * @param string $pFilename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     public function save($pFilename)
     {
@@ -181,16 +201,16 @@ class Xlsx extends BaseWriter implements IWriter
             // If $pFilename is php://output or php://stdout, make it a temporary file...
             $originalFilename = $pFilename;
             if (strtolower($pFilename) == 'php://output' || strtolower($pFilename) == 'php://stdout') {
-                $pFilename = @tempnam(\PhpOffice\PhpSpreadsheet\Shared\File::sysGetTempDir(), 'phpxltmp');
+                $pFilename = @tempnam(File::sysGetTempDir(), 'phpxltmp');
                 if ($pFilename == '') {
                     $pFilename = $originalFilename;
                 }
             }
 
-            $saveDebugLog = \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadSheet)->getDebugLog()->getWriteDebugLog();
-            \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadSheet)->getDebugLog()->setWriteDebugLog(false);
-            $saveDateReturnType = \PhpOffice\PhpSpreadsheet\Calculation\Functions::getReturnDateType();
-            \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType(\PhpOffice\PhpSpreadsheet\Calculation\Functions::RETURNDATE_EXCEL);
+            $saveDebugLog = Calculation::getInstance($this->spreadSheet)->getDebugLog()->getWriteDebugLog();
+            Calculation::getInstance($this->spreadSheet)->getDebugLog()->setWriteDebugLog(false);
+            $saveDateReturnType = Functions::getReturnDateType();
+            Functions::setReturnDateType(Functions::RETURNDATE_EXCEL);
 
             // Create string lookup table
             $this->stringTable = [];
@@ -217,7 +237,7 @@ class Xlsx extends BaseWriter implements IWriter
             // Try opening the ZIP file
             if ($zip->open($pFilename, ZipArchive::OVERWRITE) !== true) {
                 if ($zip->open($pFilename, ZipArchive::CREATE) !== true) {
-                    throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Could not open ' . $pFilename . ' for writing.');
+                    throw new WriterException('Could not open ' . $pFilename . ' for writing.');
                 }
             }
 
@@ -339,7 +359,7 @@ class Xlsx extends BaseWriter implements IWriter
 
             // Add media
             for ($i = 0; $i < $this->getDrawingHashTable()->count(); ++$i) {
-                if ($this->getDrawingHashTable()->getByIndex($i) instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing) {
+                if ($this->getDrawingHashTable()->getByIndex($i) instanceof WorksheetDrawing) {
                     $imageContents = null;
                     $imagePath = $this->getDrawingHashTable()->getByIndex($i)->getPath();
                     if (strpos($imagePath, 'zip://') !== false) {
@@ -356,7 +376,7 @@ class Xlsx extends BaseWriter implements IWriter
                     }
 
                     $zip->addFromString('xl/media/' . str_replace(' ', '_', $this->getDrawingHashTable()->getByIndex($i)->getIndexedFilename()), $imageContents);
-                } elseif ($this->getDrawingHashTable()->getByIndex($i) instanceof \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing) {
+                } elseif ($this->getDrawingHashTable()->getByIndex($i) instanceof MemoryDrawing) {
                     ob_start();
                     call_user_func(
                         $this->getDrawingHashTable()->getByIndex($i)->getRenderingFunction(),
@@ -369,30 +389,30 @@ class Xlsx extends BaseWriter implements IWriter
                 }
             }
 
-            \PhpOffice\PhpSpreadsheet\Calculation\Functions::setReturnDateType($saveDateReturnType);
-            \PhpOffice\PhpSpreadsheet\Calculation::getInstance($this->spreadSheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
+            Functions::setReturnDateType($saveDateReturnType);
+            Calculation::getInstance($this->spreadSheet)->getDebugLog()->setWriteDebugLog($saveDebugLog);
 
             // Close file
             if ($zip->close() === false) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not close zip file $pFilename.");
+                throw new WriterException("Could not close zip file $pFilename.");
             }
 
             // If a temporary file was used, copy it to the correct file stream
             if ($originalFilename != $pFilename) {
                 if (copy($pFilename, $originalFilename) === false) {
-                    throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Could not copy temporary zip file $pFilename to $originalFilename.");
+                    throw new WriterException("Could not copy temporary zip file $pFilename to $originalFilename.");
                 }
                 @unlink($pFilename);
             }
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('PhpSpreadsheet object unassigned.');
+            throw new WriterException('PhpSpreadsheet object unassigned.');
         }
     }
 
     /**
      * Get Spreadsheet object.
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return Spreadsheet
      */
@@ -401,13 +421,13 @@ class Xlsx extends BaseWriter implements IWriter
         if ($this->spreadSheet !== null) {
             return $this->spreadSheet;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('No Spreadsheet object assigned.');
+        throw new WriterException('No Spreadsheet object assigned.');
     }
 
     /**
      * Set Spreadsheet object.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet PhpSpreadsheet object
+     * @param Spreadsheet $spreadsheet PhpSpreadsheet object
      *
      * @return Xlsx
      */
@@ -429,9 +449,9 @@ class Xlsx extends BaseWriter implements IWriter
     }
 
     /**
-     * Get \PhpOffice\PhpSpreadsheet\Style HashTable.
+     * Get Style HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getStyleHashTable()
     {
@@ -439,9 +459,9 @@ class Xlsx extends BaseWriter implements IWriter
     }
 
     /**
-     * Get \PhpOffice\PhpSpreadsheet\Style\Conditional HashTable.
+     * Get Conditional HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getStylesConditionalHashTable()
     {
@@ -449,9 +469,9 @@ class Xlsx extends BaseWriter implements IWriter
     }
 
     /**
-     * Get \PhpOffice\PhpSpreadsheet\Style\Fill HashTable.
+     * Get Fill HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getFillHashTable()
     {
@@ -461,7 +481,7 @@ class Xlsx extends BaseWriter implements IWriter
     /**
      * Get \PhpOffice\PhpSpreadsheet\Style\Font HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getFontHashTable()
     {
@@ -469,9 +489,9 @@ class Xlsx extends BaseWriter implements IWriter
     }
 
     /**
-     * Get \PhpOffice\PhpSpreadsheet\Style\Borders HashTable.
+     * Get Borders HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getBordersHashTable()
     {
@@ -479,9 +499,9 @@ class Xlsx extends BaseWriter implements IWriter
     }
 
     /**
-     * Get \PhpOffice\PhpSpreadsheet\Style\NumberFormat HashTable.
+     * Get NumberFormat HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getNumFmtHashTable()
     {
@@ -491,7 +511,7 @@ class Xlsx extends BaseWriter implements IWriter
     /**
      * Get \PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing HashTable.
      *
-     * @return \PhpOffice\PhpSpreadsheet\HashTable
+     * @return HashTable
      */
     public function getDrawingHashTable()
     {
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Chart.php b/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
index 418688f7..a86b1a88 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Chart.php
@@ -10,6 +10,9 @@ use PhpOffice\PhpSpreadsheet\Chart\Layout;
 use PhpOffice\PhpSpreadsheet\Chart\Legend;
 use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
 use PhpOffice\PhpSpreadsheet\Chart\Title;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
@@ -43,7 +46,7 @@ class Chart extends WriterPart
      * @param \PhpOffice\PhpSpreadsheet\Chart $pChart
      * @param mixed $calculateCellValues
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -54,9 +57,9 @@ class Chart extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
         //    Ensure that data series values are up-to-date before we save
         if ($this->calculateCellValues) {
@@ -121,12 +124,12 @@ class Chart extends WriterPart
     /**
      * Write Chart Title.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param Title $title
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeTitle(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, Title $title = null)
+    private function writeTitle(XMLWriter $objWriter, Title $title = null)
     {
         if (is_null($title)) {
             return;
@@ -166,12 +169,12 @@ class Chart extends WriterPart
     /**
      * Write Chart Legend.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param Legend $legend
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeLegend(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, Legend $legend = null)
+    private function writeLegend(XMLWriter $objWriter, Legend $legend = null)
     {
         if (is_null($legend)) {
             return;
@@ -217,7 +220,7 @@ class Chart extends WriterPart
     /**
      * Write Chart Plot Area.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
      * @param PlotArea $plotArea
      * @param Title $xAxisLabel
@@ -225,9 +228,9 @@ class Chart extends WriterPart
      * @param Axis $xAxis
      * @param Axis $yAxis
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writePlotArea(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, PlotArea $plotArea, Title $xAxisLabel = null, Title $yAxisLabel = null, Axis $xAxis = null, Axis $yAxis = null, GridLines $majorGridlines = null, GridLines $minorGridlines = null)
+    private function writePlotArea(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, PlotArea $plotArea, Title $xAxisLabel = null, Title $yAxisLabel = null, Axis $xAxis = null, Axis $yAxis = null, GridLines $majorGridlines = null, GridLines $minorGridlines = null)
     {
         if (is_null($plotArea)) {
             return;
@@ -353,12 +356,12 @@ class Chart extends WriterPart
     /**
      * Write Data Labels.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Chart\Layout $chartLayout Chart layout
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDataLabels(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, Layout $chartLayout = null)
+    private function writeDataLabels(XMLWriter $objWriter, Layout $chartLayout = null)
     {
         $objWriter->startElement('c:dLbls');
 
@@ -403,7 +406,7 @@ class Chart extends WriterPart
     /**
      * Write Category Axis.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param PlotArea $plotArea
      * @param Title $xAxisLabel
      * @param string $groupType Chart type
@@ -413,7 +416,7 @@ class Chart extends WriterPart
      * @param mixed $xAxis
      * @param mixed $yAxis
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writeCategoryAxis($objWriter, PlotArea $plotArea, $xAxisLabel, $groupType, $id1, $id2, $isMultiLevelSeries, $xAxis, $yAxis)
     {
@@ -458,7 +461,7 @@ class Chart extends WriterPart
                 $caption = $caption[0];
             }
             $objWriter->startElement('a:t');
-            $objWriter->writeRawData(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML($caption));
+            $objWriter->writeRawData(StringHelper::controlCharacterPHP2OOXML($caption));
             $objWriter->endElement();
 
             $objWriter->endElement();
@@ -526,7 +529,7 @@ class Chart extends WriterPart
     /**
      * Write Value Axis.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param PlotArea $plotArea
      * @param Title $yAxisLabel
      * @param string $groupType Chart type
@@ -538,7 +541,7 @@ class Chart extends WriterPart
      * @param mixed $majorGridlines
      * @param mixed $minorGridlines
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writeValueAxis($objWriter, PlotArea $plotArea, $yAxisLabel, $groupType, $id1, $id2, $isMultiLevelSeries, $xAxis, $yAxis, $majorGridlines, $minorGridlines)
     {
@@ -811,7 +814,7 @@ class Chart extends WriterPart
             }
 
             $objWriter->startElement('a:t');
-            $objWriter->writeRawData(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML($caption));
+            $objWriter->writeRawData(StringHelper::controlCharacterPHP2OOXML($caption));
             $objWriter->endElement();
 
             $objWriter->endElement();
@@ -1018,7 +1021,7 @@ class Chart extends WriterPart
      *
      * @param PlotArea $plotArea
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string|array
      */
@@ -1035,7 +1038,7 @@ class Chart extends WriterPart
             }
             $chartType = array_unique($chartTypes);
             if (count($chartTypes) == 0) {
-                throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Chart is not yet implemented');
+                throw new WriterException('Chart is not yet implemented');
             }
         }
 
@@ -1047,13 +1050,13 @@ class Chart extends WriterPart
      *
      * @param DataSeries $plotGroup
      * @param string $groupType Type of plot for dataseries
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param bool &$catIsMultiLevelSeries Is category a multi-series category
      * @param bool &$valIsMultiLevelSeries Is value set a multi-series set
      * @param string &$plotGroupingType Type of grouping for multi-series values
      * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writePlotGroup($plotGroup, $groupType, $objWriter, &$catIsMultiLevelSeries, &$valIsMultiLevelSeries, &$plotGroupingType, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
     {
@@ -1225,9 +1228,9 @@ class Chart extends WriterPart
      * Write Plot Series Label.
      *
      * @param DataSeriesValues $plotSeriesLabel
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writePlotSeriesLabel($plotSeriesLabel, $objWriter)
     {
@@ -1260,13 +1263,13 @@ class Chart extends WriterPart
      * Write Plot Series Values.
      *
      * @param DataSeriesValues $plotSeriesValues
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $groupType Type of plot for dataseries
      * @param string $dataType Datatype of series values
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writePlotSeriesValues($plotSeriesValues, \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $groupType, $dataType = 'str')
+    private function writePlotSeriesValues($plotSeriesValues, XMLWriter $objWriter, $groupType, $dataType = 'str')
     {
         if (is_null($plotSeriesValues)) {
             return;
@@ -1354,9 +1357,9 @@ class Chart extends WriterPart
      * Write Bubble Chart Details.
      *
      * @param DataSeriesValues $plotSeriesValues
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writeBubbles($plotSeriesValues, $objWriter)
     {
@@ -1400,12 +1403,12 @@ class Chart extends WriterPart
     /**
      * Write Layout.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param Layout $layout
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeLayout(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, Layout $layout = null)
+    private function writeLayout(XMLWriter $objWriter, Layout $layout = null)
     {
         $objWriter->startElement('c:layout');
 
@@ -1470,9 +1473,9 @@ class Chart extends WriterPart
     /**
      * Write Alternate Content block.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writeAlternateContent($objWriter)
     {
@@ -1500,9 +1503,9 @@ class Chart extends WriterPart
     /**
      * Write Printer Settings.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
     private function writePrintSettings($objWriter)
     {
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Comments.php b/src/PhpSpreadsheet/Writer/Xlsx/Comments.php
index e630b797..d08f3aec 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Comments.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Comments.php
@@ -2,6 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Comment;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -40,9 +44,9 @@ class Comments extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -87,14 +91,14 @@ class Comments extends WriterPart
     /**
      * Write comment to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pCellReference Cell reference
-     * @param \PhpOffice\PhpSpreadsheet\Comment $pComment Comment
+     * @param Comment $pComment Comment
      * @param array $pAuthors Array of authors
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeComment(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pCellReference, \PhpOffice\PhpSpreadsheet\Comment $pComment, array $pAuthors)
+    private function writeComment(XMLWriter $objWriter, $pCellReference, Comment $pComment, array $pAuthors)
     {
         // comment
         $objWriter->startElement('comment');
@@ -123,9 +127,9 @@ class Comments extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -186,17 +190,17 @@ class Comments extends WriterPart
     /**
      * Write VML comment to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pCellReference Cell reference, eg: 'A1'
-     * @param \PhpOffice\PhpSpreadsheet\Comment $pComment Comment
+     * @param Comment $pComment Comment
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeVMLComment(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pCellReference, \PhpOffice\PhpSpreadsheet\Comment $pComment)
+    private function writeVMLComment(XMLWriter $objWriter, $pCellReference, Comment $pComment)
     {
         // Metadata
-        list($column, $row) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($pCellReference);
-        $column = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($column);
+        list($column, $row) = Cell::coordinateFromString($pCellReference);
+        $column = Cell::columnIndexFromString($column);
         $id = 1024 + $column + $row;
         $id = substr($id, 0, 4);
 
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/ContentTypes.php b/src/PhpSpreadsheet/Writer/Xlsx/ContentTypes.php
index bf01e978..64a14602 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/ContentTypes.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/ContentTypes.php
@@ -2,6 +2,12 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,21 +35,21 @@ class ContentTypes extends WriterPart
     /**
      * Write content types to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      * @param bool $includeCharts Flag indicating if we should include drawing details for charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
-    public function writeContentTypes(\PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet, $includeCharts = false)
+    public function writeContentTypes(Spreadsheet $spreadsheet, $includeCharts = false)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -140,7 +146,7 @@ class ContentTypes extends WriterPart
             if ($this->getParentWriter()->getDrawingHashTable()->getByIndex($i) instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing) {
                 $extension = strtolower($this->getParentWriter()->getDrawingHashTable()->getByIndex($i)->getExtension());
                 $mimeType = $this->getImageMimeType($this->getParentWriter()->getDrawingHashTable()->getByIndex($i)->getPath());
-            } elseif ($this->getParentWriter()->getDrawingHashTable()->getByIndex($i) instanceof \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing) {
+            } elseif ($this->getParentWriter()->getDrawingHashTable()->getByIndex($i) instanceof MemoryDrawing) {
                 $extension = strtolower($this->getParentWriter()->getDrawingHashTable()->getByIndex($i)->getMimeType());
                 $extension = explode('/', $extension);
                 $extension = $extension[1];
@@ -187,30 +193,30 @@ class ContentTypes extends WriterPart
      *
      * @param string $pFile Filename
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string Mime Type
      */
     private function getImageMimeType($pFile)
     {
-        if (\PhpOffice\PhpSpreadsheet\Shared\File::fileExists($pFile)) {
+        if (File::fileExists($pFile)) {
             $image = getimagesize($pFile);
 
             return image_type_to_mime_type($image[2]);
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("File $pFile does not exist");
+        throw new WriterException("File $pFile does not exist");
     }
 
     /**
      * Write Default content type.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pPartname Part name
      * @param string $pContentType Content type
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefaultContentType(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pPartname, $pContentType)
+    private function writeDefaultContentType(XMLWriter $objWriter, $pPartname, $pContentType)
     {
         if ($pPartname != '' && $pContentType != '') {
             // Write content type
@@ -219,20 +225,20 @@ class ContentTypes extends WriterPart
             $objWriter->writeAttribute('ContentType', $pContentType);
             $objWriter->endElement();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid parameters passed.');
+            throw new WriterException('Invalid parameters passed.');
         }
     }
 
     /**
      * Write Override content type.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pPartname Part name
      * @param string $pContentType Content type
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeOverrideContentType(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pPartname, $pContentType)
+    private function writeOverrideContentType(XMLWriter $objWriter, $pPartname, $pContentType)
     {
         if ($pPartname != '' && $pContentType != '') {
             // Write content type
@@ -241,7 +247,7 @@ class ContentTypes extends WriterPart
             $objWriter->writeAttribute('ContentType', $pContentType);
             $objWriter->endElement();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid parameters passed.');
+            throw new WriterException('Invalid parameters passed.');
         }
     }
 }
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/DocProps.php b/src/PhpSpreadsheet/Writer/Xlsx/DocProps.php
index 7eb9a06e..3de9b5a8 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/DocProps.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/DocProps.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +32,20 @@ class DocProps extends WriterPart
     /**
      * Write docProps/app.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeDocPropsApp(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeDocPropsApp(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -128,20 +131,20 @@ class DocProps extends WriterPart
     /**
      * Write docProps/core.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeDocPropsCore(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeDocPropsCore(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -197,13 +200,13 @@ class DocProps extends WriterPart
     /**
      * Write docProps/custom.xml to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeDocPropsCustom(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeDocPropsCustom(Spreadsheet $spreadsheet)
     {
         $customPropertyList = $spreadsheet->getProperties()->getCustomProperties();
         if (empty($customPropertyList)) {
@@ -213,9 +216,9 @@ class DocProps extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Drawing.php b/src/PhpSpreadsheet/Writer/Xlsx/Drawing.php
index afd27f30..41092f55 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Drawing.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Drawing.php
@@ -2,6 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing;
+use PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooterDrawing;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -33,7 +40,7 @@ class Drawing extends WriterPart
      * @param int &$chartRef Chart ID
      * @param bool $includeCharts Flag indicating if we should include drawing details for charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -42,9 +49,9 @@ class Drawing extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -84,29 +91,29 @@ class Drawing extends WriterPart
     /**
      * Write drawings to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Chart $pChart
      * @param int $pRelationId
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    public function writeChart(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Chart $pChart, $pRelationId = -1)
+    public function writeChart(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Chart $pChart, $pRelationId = -1)
     {
         $tl = $pChart->getTopLeftPosition();
-        $tl['colRow'] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($tl['cell']);
+        $tl['colRow'] = Cell::coordinateFromString($tl['cell']);
         $br = $pChart->getBottomRightPosition();
-        $br['colRow'] = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($br['cell']);
+        $br['colRow'] = Cell::coordinateFromString($br['cell']);
 
         $objWriter->startElement('xdr:twoCellAnchor');
 
         $objWriter->startElement('xdr:from');
-        $objWriter->writeElement('xdr:col', \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($tl['colRow'][0]) - 1);
+        $objWriter->writeElement('xdr:col', Cell::columnIndexFromString($tl['colRow'][0]) - 1);
         $objWriter->writeElement('xdr:colOff', \PhpOffice\PhpSpreadsheet\Shared\Drawing::pixelsToEMU($tl['xOffset']));
         $objWriter->writeElement('xdr:row', $tl['colRow'][1] - 1);
         $objWriter->writeElement('xdr:rowOff', \PhpOffice\PhpSpreadsheet\Shared\Drawing::pixelsToEMU($tl['yOffset']));
         $objWriter->endElement();
         $objWriter->startElement('xdr:to');
-        $objWriter->writeElement('xdr:col', \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($br['colRow'][0]) - 1);
+        $objWriter->writeElement('xdr:col', Cell::columnIndexFromString($br['colRow'][0]) - 1);
         $objWriter->writeElement('xdr:colOff', \PhpOffice\PhpSpreadsheet\Shared\Drawing::pixelsToEMU($br['xOffset']));
         $objWriter->writeElement('xdr:row', $br['colRow'][1] - 1);
         $objWriter->writeElement('xdr:rowOff', \PhpOffice\PhpSpreadsheet\Shared\Drawing::pixelsToEMU($br['yOffset']));
@@ -157,20 +164,20 @@ class Drawing extends WriterPart
     /**
      * Write drawings to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing $pDrawing
+     * @param XMLWriter $objWriter XML Writer
+     * @param BaseDrawing $pDrawing
      * @param int $pRelationId
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    public function writeDrawing(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet\BaseDrawing $pDrawing, $pRelationId = -1)
+    public function writeDrawing(XMLWriter $objWriter, BaseDrawing $pDrawing, $pRelationId = -1)
     {
         if ($pRelationId >= 0) {
             // xdr:oneCellAnchor
             $objWriter->startElement('xdr:oneCellAnchor');
             // Image location
-            $aCoordinates = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($pDrawing->getCoordinates());
-            $aCoordinates[0] = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($aCoordinates[0]);
+            $aCoordinates = Cell::coordinateFromString($pDrawing->getCoordinates());
+            $aCoordinates[0] = Cell::columnIndexFromString($aCoordinates[0]);
 
             // xdr:from
             $objWriter->startElement('xdr:from');
@@ -280,7 +287,7 @@ class Drawing extends WriterPart
 
             $objWriter->endElement();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid parameters passed.');
+            throw new WriterException('Invalid parameters passed.');
         }
     }
 
@@ -289,7 +296,7 @@ class Drawing extends WriterPart
      *
      * @param \PhpOffice\PhpSpreadsheet\Worksheet $pWorksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -298,9 +305,9 @@ class Drawing extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -436,13 +443,13 @@ class Drawing extends WriterPart
     /**
      * Write VML comment to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pReference Reference
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooterDrawing $pImage Image
+     * @param HeaderFooterDrawing $pImage Image
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeVMLHeaderFooterImage(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pReference, \PhpOffice\PhpSpreadsheet\Worksheet\HeaderFooterDrawing $pImage)
+    private function writeVMLHeaderFooterImage(XMLWriter $objWriter, $pReference, HeaderFooterDrawing $pImage)
     {
         // Calculate object id
         preg_match('{(\d+)}', md5($pReference), $m);
@@ -479,13 +486,13 @@ class Drawing extends WriterPart
     /**
      * Get an array of all drawings.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return \PhpOffice\PhpSpreadsheet\Worksheet\Drawing[] All drawings in PhpSpreadsheet
      */
-    public function allDrawings(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allDrawings(Spreadsheet $spreadsheet)
     {
         // Get an array of all drawings
         $aDrawings = [];
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Rels.php b/src/PhpSpreadsheet/Writer/Xlsx/Rels.php
index 2d4ceef5..eec3cefa 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Rels.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Rels.php
@@ -2,6 +2,11 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +34,20 @@ class Rels extends WriterPart
     /**
      * Write relationships to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
-    public function writeRelationships(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeRelationships(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -104,20 +109,20 @@ class Rels extends WriterPart
     /**
      * Write workbook relationships to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
-    public function writeWorkbookRelationships(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeWorkbookRelationships(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -189,7 +194,7 @@ class Rels extends WriterPart
      * @param int $pWorksheetId
      * @param bool $includeCharts Flag indicating if we should write charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -198,9 +203,9 @@ class Rels extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -284,7 +289,7 @@ class Rels extends WriterPart
      * @param int &$chartRef Chart ID
      * @param bool $includeCharts Flag indicating if we should write charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -293,9 +298,9 @@ class Rels extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -310,7 +315,7 @@ class Rels extends WriterPart
         $iterator = $pWorksheet->getDrawingCollection()->getIterator();
         while ($iterator->valid()) {
             if ($iterator->current() instanceof \PhpOffice\PhpSpreadsheet\Worksheet\Drawing
-                || $iterator->current() instanceof \PhpOffice\PhpSpreadsheet\Worksheet\MemoryDrawing) {
+                || $iterator->current() instanceof MemoryDrawing) {
                 // Write relationship for image drawing
                 $this->writeRelationship(
                     $objWriter,
@@ -349,7 +354,7 @@ class Rels extends WriterPart
      *
      * @param \PhpOffice\PhpSpreadsheet\Worksheet $pWorksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -358,9 +363,9 @@ class Rels extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -389,15 +394,15 @@ class Rels extends WriterPart
     /**
      * Write Override content type.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param int $pId Relationship ID. rId will be prepended!
      * @param string $pType Relationship type
      * @param string $pTarget Relationship target
      * @param string $pTargetMode Relationship target mode
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeRelationship(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pId, $pType, $pTarget, $pTargetMode = '')
+    private function writeRelationship(XMLWriter $objWriter, $pId, $pType, $pTarget, $pTargetMode = '')
     {
         if ($pType != '' && $pTarget != '') {
             // Write relationship
@@ -412,7 +417,7 @@ class Rels extends WriterPart
 
             $objWriter->endElement();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid parameters passed.');
+            throw new WriterException('Invalid parameters passed.');
         }
     }
 }
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/RelsRibbon.php b/src/PhpSpreadsheet/Writer/Xlsx/RelsRibbon.php
index da414a2f..e827d182 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/RelsRibbon.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/RelsRibbon.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +32,20 @@ class RelsRibbon extends WriterPart
     /**
      * Write relationships for additional objects of custom UI (ribbon).
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeRibbonRelationships(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeRibbonRelationships(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/RelsVBA.php b/src/PhpSpreadsheet/Writer/Xlsx/RelsVBA.php
index dbf4dfed..8bd7de13 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/RelsVBA.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/RelsVBA.php
@@ -2,6 +2,9 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +32,20 @@ class RelsVBA extends WriterPart
     /**
      * Write relationships for a signed VBA Project.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeVBARelationships(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeVBARelationships(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php b/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
index 4232445a..8b141e1b 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/StringTable.php
@@ -2,6 +2,12 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,10 +35,10 @@ class StringTable extends WriterPart
     /**
      * Create worksheet stringtable.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param Worksheet $pSheet Worksheet
      * @param string[] $pExistingTable Existing table to eventually merge with
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string[] String table for worksheet
      */
@@ -60,10 +66,10 @@ class StringTable extends WriterPart
                     ($cellValue !== null) &&
                     $cellValue !== '' &&
                     !isset($aFlippedStringTable[$cellValue]) &&
-                    ($cell->getDataType() == \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING || $cell->getDataType() == \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_STRING2 || $cell->getDataType() == \PhpOffice\PhpSpreadsheet\Cell\DataType::TYPE_NULL)) {
+                    ($cell->getDataType() == Cell\DataType::TYPE_STRING || $cell->getDataType() == Cell\DataType::TYPE_STRING2 || $cell->getDataType() == Cell\DataType::TYPE_NULL)) {
                     $aStringTable[] = $cellValue;
                     $aFlippedStringTable[$cellValue] = true;
-                } elseif ($cellValue instanceof \PhpOffice\PhpSpreadsheet\RichText &&
+                } elseif ($cellValue instanceof RichText &&
                           ($cellValue !== null) &&
                           !isset($aFlippedStringTable[$cellValue->getHashCode()])) {
                     $aStringTable[] = $cellValue;
@@ -73,7 +79,7 @@ class StringTable extends WriterPart
 
             return $aStringTable;
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception("Invalid \PhpOffice\PhpSpreadsheet\Worksheet object passed.");
+        throw new WriterException('Invalid Worksheet object passed.');
     }
 
     /**
@@ -81,7 +87,7 @@ class StringTable extends WriterPart
      *
      * @param string[] $pStringTable
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -90,9 +96,9 @@ class StringTable extends WriterPart
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -107,15 +113,15 @@ class StringTable extends WriterPart
         foreach ($pStringTable as $textElement) {
             $objWriter->startElement('si');
 
-            if (!$textElement instanceof \PhpOffice\PhpSpreadsheet\RichText) {
-                $textToWrite = \PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML($textElement);
+            if (!$textElement instanceof RichText) {
+                $textToWrite = StringHelper::controlCharacterPHP2OOXML($textElement);
                 $objWriter->startElement('t');
                 if ($textToWrite !== trim($textToWrite)) {
                     $objWriter->writeAttribute('xml:space', 'preserve');
                 }
                 $objWriter->writeRawData($textToWrite);
                 $objWriter->endElement();
-            } elseif ($textElement instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+            } elseif ($textElement instanceof RichText) {
                 $this->writeRichText($objWriter, $textElement);
             }
 
@@ -130,13 +136,13 @@ class StringTable extends WriterPart
     /**
      * Write Rich Text.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\RichText $pRichText Rich text
+     * @param XMLWriter $objWriter XML Writer
+     * @param RichText $pRichText Rich text
      * @param string $prefix Optional Namespace prefix
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    public function writeRichText(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\RichText $pRichText, $prefix = null)
+    public function writeRichText(XMLWriter $objWriter, RichText $pRichText, $prefix = null)
     {
         if ($prefix !== null) {
             $prefix .= ':';
@@ -149,7 +155,7 @@ class StringTable extends WriterPart
             $objWriter->startElement($prefix . 'r');
 
             // rPr
-            if ($element instanceof \PhpOffice\PhpSpreadsheet\RichText\Run) {
+            if ($element instanceof RichText\Run) {
                 // rPr
                 $objWriter->startElement($prefix . 'rPr');
 
@@ -205,7 +211,7 @@ class StringTable extends WriterPart
             // t
             $objWriter->startElement($prefix . 't');
             $objWriter->writeAttribute('xml:space', 'preserve');
-            $objWriter->writeRawData(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML($element->getText()));
+            $objWriter->writeRawData(StringHelper::controlCharacterPHP2OOXML($element->getText()));
             $objWriter->endElement();
 
             $objWriter->endElement();
@@ -215,17 +221,17 @@ class StringTable extends WriterPart
     /**
      * Write Rich Text.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param string|\PhpOffice\PhpSpreadsheet\RichText $pRichText text string or Rich text
+     * @param XMLWriter $objWriter XML Writer
+     * @param string|RichText $pRichText text string or Rich text
      * @param string $prefix Optional Namespace prefix
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    public function writeRichTextForCharts(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pRichText = null, $prefix = null)
+    public function writeRichTextForCharts(XMLWriter $objWriter, $pRichText = null, $prefix = null)
     {
-        if (!$pRichText instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+        if (!$pRichText instanceof RichText) {
             $textRun = $pRichText;
-            $pRichText = new \PhpOffice\PhpSpreadsheet\RichText();
+            $pRichText = new RichText();
             $pRichText->createTextRun($textRun);
         }
 
@@ -269,7 +275,7 @@ class StringTable extends WriterPart
 
             // t
             $objWriter->startElement($prefix . 't');
-            $objWriter->writeRawData(\PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML($element->getText()));
+            $objWriter->writeRawData(StringHelper::controlCharacterPHP2OOXML($element->getText()));
             $objWriter->endElement();
 
             $objWriter->endElement();
@@ -290,9 +296,9 @@ class StringTable extends WriterPart
 
         // Loop through stringtable and add flipped items to $returnValue
         foreach ($stringTable as $key => $value) {
-            if (!$value instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+            if (!$value instanceof RichText) {
                 $returnValue[$value] = $key;
-            } elseif ($value instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+            } elseif ($value instanceof RichText) {
                 $returnValue[$value->getHashCode()] = $key;
             }
         }
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Style.php b/src/PhpSpreadsheet/Writer/Xlsx/Style.php
index 96457aa1..da49970d 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Style.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Style.php
@@ -2,6 +2,16 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Style\Border;
+use PhpOffice\PhpSpreadsheet\Style\Borders;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
+use PhpOffice\PhpSpreadsheet\Style\Font;
+use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PhpOffice\PhpSpreadsheet\Style\Protection;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +39,20 @@ class Style extends WriterPart
     /**
      * Write styles to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeStyles(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeStyles(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -161,16 +171,16 @@ class Style extends WriterPart
     /**
      * Write Fill.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\Fill $pFill Fill style
+     * @param XMLWriter $objWriter XML Writer
+     * @param Fill $pFill Fill style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeFill(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\Fill $pFill)
+    private function writeFill(XMLWriter $objWriter, Fill $pFill)
     {
         // Check if this is a pattern type or gradient type
-        if ($pFill->getFillType() === \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_LINEAR ||
-            $pFill->getFillType() === \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_GRADIENT_PATH) {
+        if ($pFill->getFillType() === Fill::FILL_GRADIENT_LINEAR ||
+            $pFill->getFillType() === Fill::FILL_GRADIENT_PATH) {
             // Gradient fill
             $this->writeGradientFill($objWriter, $pFill);
         } elseif ($pFill->getFillType() !== null) {
@@ -182,12 +192,12 @@ class Style extends WriterPart
     /**
      * Write Gradient Fill.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\Fill $pFill Fill style
+     * @param XMLWriter $objWriter XML Writer
+     * @param Fill $pFill Fill style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeGradientFill(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\Fill $pFill)
+    private function writeGradientFill(XMLWriter $objWriter, Fill $pFill)
     {
         // fill
         $objWriter->startElement('fill');
@@ -227,12 +237,12 @@ class Style extends WriterPart
     /**
      * Write Pattern Fill.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\Fill $pFill Fill style
+     * @param XMLWriter $objWriter XML Writer
+     * @param Fill $pFill Fill style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writePatternFill(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\Fill $pFill)
+    private function writePatternFill(XMLWriter $objWriter, Fill $pFill)
     {
         // fill
         $objWriter->startElement('fill');
@@ -241,7 +251,7 @@ class Style extends WriterPart
         $objWriter->startElement('patternFill');
         $objWriter->writeAttribute('patternType', $pFill->getFillType());
 
-        if ($pFill->getFillType() !== \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE) {
+        if ($pFill->getFillType() !== Fill::FILL_NONE) {
             // fgColor
             if ($pFill->getStartColor()->getARGB()) {
                 $objWriter->startElement('fgColor');
@@ -249,7 +259,7 @@ class Style extends WriterPart
                 $objWriter->endElement();
             }
         }
-        if ($pFill->getFillType() !== \PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE) {
+        if ($pFill->getFillType() !== Fill::FILL_NONE) {
             // bgColor
             if ($pFill->getEndColor()->getARGB()) {
                 $objWriter->startElement('bgColor');
@@ -266,12 +276,12 @@ class Style extends WriterPart
     /**
      * Write Font.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\Font $pFont Font style
+     * @param XMLWriter $objWriter XML Writer
+     * @param Font $pFont Font style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeFont(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\Font $pFont)
+    private function writeFont(XMLWriter $objWriter, Font $pFont)
     {
         // font
         $objWriter->startElement('font');
@@ -323,7 +333,7 @@ class Style extends WriterPart
         // Size
         if ($pFont->getSize() !== null) {
             $objWriter->startElement('sz');
-            $objWriter->writeAttribute('val', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pFont->getSize()));
+            $objWriter->writeAttribute('val', StringHelper::formatNumber($pFont->getSize()));
             $objWriter->endElement();
         }
 
@@ -347,26 +357,26 @@ class Style extends WriterPart
     /**
      * Write Border.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\Borders $pBorders Borders style
+     * @param XMLWriter $objWriter XML Writer
+     * @param Borders $pBorders Borders style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeBorder(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\Borders $pBorders)
+    private function writeBorder(XMLWriter $objWriter, Borders $pBorders)
     {
         // Write border
         $objWriter->startElement('border');
         // Diagonal?
         switch ($pBorders->getDiagonalDirection()) {
-            case \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_UP:
+            case Borders::DIAGONAL_UP:
                 $objWriter->writeAttribute('diagonalUp', 'true');
                 $objWriter->writeAttribute('diagonalDown', 'false');
                 break;
-            case \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_DOWN:
+            case Borders::DIAGONAL_DOWN:
                 $objWriter->writeAttribute('diagonalUp', 'false');
                 $objWriter->writeAttribute('diagonalDown', 'true');
                 break;
-            case \PhpOffice\PhpSpreadsheet\Style\Borders::DIAGONAL_BOTH:
+            case Borders::DIAGONAL_BOTH:
                 $objWriter->writeAttribute('diagonalUp', 'true');
                 $objWriter->writeAttribute('diagonalDown', 'true');
                 break;
@@ -384,13 +394,13 @@ class Style extends WriterPart
     /**
      * Write Cell Style Xf.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Style $pStyle Style
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet Workbook
+     * @param Spreadsheet $spreadsheet Workbook
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeCellStyleXf(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style $pStyle, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeCellStyleXf(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style $pStyle, Spreadsheet $spreadsheet)
     {
         // xf
         $objWriter->startElement('xf');
@@ -415,7 +425,7 @@ class Style extends WriterPart
         $objWriter->writeAttribute('applyFill', ($spreadsheet->getDefaultStyle()->getFill()->getHashCode() != $pStyle->getFill()->getHashCode()) ? '1' : '0');
         $objWriter->writeAttribute('applyBorder', ($spreadsheet->getDefaultStyle()->getBorders()->getHashCode() != $pStyle->getBorders()->getHashCode()) ? '1' : '0');
         $objWriter->writeAttribute('applyAlignment', ($spreadsheet->getDefaultStyle()->getAlignment()->getHashCode() != $pStyle->getAlignment()->getHashCode()) ? '1' : '0');
-        if ($pStyle->getProtection()->getLocked() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT || $pStyle->getProtection()->getHidden() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT) {
+        if ($pStyle->getProtection()->getLocked() != Protection::PROTECTION_INHERIT || $pStyle->getProtection()->getHidden() != Protection::PROTECTION_INHERIT) {
             $objWriter->writeAttribute('applyProtection', 'true');
         }
 
@@ -444,13 +454,13 @@ class Style extends WriterPart
         $objWriter->endElement();
 
         // protection
-        if ($pStyle->getProtection()->getLocked() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT || $pStyle->getProtection()->getHidden() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT) {
+        if ($pStyle->getProtection()->getLocked() != Protection::PROTECTION_INHERIT || $pStyle->getProtection()->getHidden() != Protection::PROTECTION_INHERIT) {
             $objWriter->startElement('protection');
-            if ($pStyle->getProtection()->getLocked() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT) {
-                $objWriter->writeAttribute('locked', ($pStyle->getProtection()->getLocked() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
+            if ($pStyle->getProtection()->getLocked() != Protection::PROTECTION_INHERIT) {
+                $objWriter->writeAttribute('locked', ($pStyle->getProtection()->getLocked() == Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
             }
-            if ($pStyle->getProtection()->getHidden() != \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT) {
-                $objWriter->writeAttribute('hidden', ($pStyle->getProtection()->getHidden() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
+            if ($pStyle->getProtection()->getHidden() != Protection::PROTECTION_INHERIT) {
+                $objWriter->writeAttribute('hidden', ($pStyle->getProtection()->getHidden() == Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
             }
             $objWriter->endElement();
         }
@@ -461,12 +471,12 @@ class Style extends WriterPart
     /**
      * Write Cell Style Dxf.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param \PhpOffice\PhpSpreadsheet\Style $pStyle Style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeCellStyleDxf(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style $pStyle)
+    private function writeCellStyleDxf(XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style $pStyle)
     {
         // dxf
         $objWriter->startElement('dxf');
@@ -505,16 +515,16 @@ class Style extends WriterPart
 
         // protection
         if (($pStyle->getProtection()->getLocked() !== null) || ($pStyle->getProtection()->getHidden() !== null)) {
-            if ($pStyle->getProtection()->getLocked() !== \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT ||
-                $pStyle->getProtection()->getHidden() !== \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT) {
+            if ($pStyle->getProtection()->getLocked() !== Protection::PROTECTION_INHERIT ||
+                $pStyle->getProtection()->getHidden() !== Protection::PROTECTION_INHERIT) {
                 $objWriter->startElement('protection');
                 if (($pStyle->getProtection()->getLocked() !== null) &&
-                    ($pStyle->getProtection()->getLocked() !== \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT)) {
-                    $objWriter->writeAttribute('locked', ($pStyle->getProtection()->getLocked() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
+                    ($pStyle->getProtection()->getLocked() !== Protection::PROTECTION_INHERIT)) {
+                    $objWriter->writeAttribute('locked', ($pStyle->getProtection()->getLocked() == Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
                 }
                 if (($pStyle->getProtection()->getHidden() !== null) &&
-                    ($pStyle->getProtection()->getHidden() !== \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_INHERIT)) {
-                    $objWriter->writeAttribute('hidden', ($pStyle->getProtection()->getHidden() == \PhpOffice\PhpSpreadsheet\Style\Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
+                    ($pStyle->getProtection()->getHidden() !== Protection::PROTECTION_INHERIT)) {
+                    $objWriter->writeAttribute('hidden', ($pStyle->getProtection()->getHidden() == Protection::PROTECTION_PROTECTED ? 'true' : 'false'));
                 }
                 $objWriter->endElement();
             }
@@ -526,16 +536,16 @@ class Style extends WriterPart
     /**
      * Write BorderPr.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pName Element name
-     * @param \PhpOffice\PhpSpreadsheet\Style\Border $pBorder Border style
+     * @param Border $pBorder Border style
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeBorderPr(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pName, \PhpOffice\PhpSpreadsheet\Style\Border $pBorder)
+    private function writeBorderPr(XMLWriter $objWriter, $pName, Border $pBorder)
     {
         // Write BorderPr
-        if ($pBorder->getBorderStyle() != \PhpOffice\PhpSpreadsheet\Style\Border::BORDER_NONE) {
+        if ($pBorder->getBorderStyle() != Border::BORDER_NONE) {
             $objWriter->startElement($pName);
             $objWriter->writeAttribute('style', $pBorder->getBorderStyle());
 
@@ -551,13 +561,13 @@ class Style extends WriterPart
     /**
      * Write NumberFormat.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Style\NumberFormat $pNumberFormat Number Format
+     * @param XMLWriter $objWriter XML Writer
+     * @param NumberFormat $pNumberFormat Number Format
      * @param int $pId Number Format identifier
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      */
-    private function writeNumFmt(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Style\NumberFormat $pNumberFormat, $pId = 0)
+    private function writeNumFmt(XMLWriter $objWriter, NumberFormat $pNumberFormat, $pId = 0)
     {
         // Translate formatcode
         $formatCode = $pNumberFormat->getFormatCode();
@@ -574,13 +584,13 @@ class Style extends WriterPart
     /**
      * Get an array of all styles.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return \PhpOffice\PhpSpreadsheet\Style[] All styles in PhpSpreadsheet
      */
-    public function allStyles(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allStyles(Spreadsheet $spreadsheet)
     {
         return $spreadsheet->getCellXfCollection();
     }
@@ -588,13 +598,13 @@ class Style extends WriterPart
     /**
      * Get an array of all conditional styles.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Conditional[] All conditional styles in PhpSpreadsheet
+     * @return Conditional[] All conditional styles in PhpSpreadsheet
      */
-    public function allConditionalStyles(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allConditionalStyles(Spreadsheet $spreadsheet)
     {
         // Get an array of all styles
         $aStyles = [];
@@ -614,24 +624,24 @@ class Style extends WriterPart
     /**
      * Get an array of all fills.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Fill[] All fills in PhpSpreadsheet
+     * @return Fill[] All fills in PhpSpreadsheet
      */
-    public function allFills(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allFills(Spreadsheet $spreadsheet)
     {
         // Get an array of unique fills
         $aFills = [];
 
         // Two first fills are predefined
-        $fill0 = new \PhpOffice\PhpSpreadsheet\Style\Fill();
-        $fill0->setFillType(\PhpOffice\PhpSpreadsheet\Style\Fill::FILL_NONE);
+        $fill0 = new Fill();
+        $fill0->setFillType(Fill::FILL_NONE);
         $aFills[] = $fill0;
 
-        $fill1 = new \PhpOffice\PhpSpreadsheet\Style\Fill();
-        $fill1->setFillType(\PhpOffice\PhpSpreadsheet\Style\Fill::FILL_PATTERN_GRAY125);
+        $fill1 = new Fill();
+        $fill1->setFillType(Fill::FILL_PATTERN_GRAY125);
         $aFills[] = $fill1;
         // The remaining fills
         $aStyles = $this->allStyles($spreadsheet);
@@ -648,13 +658,13 @@ class Style extends WriterPart
     /**
      * Get an array of all fonts.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Font[] All fonts in PhpSpreadsheet
+     * @return Font[] All fonts in PhpSpreadsheet
      */
-    public function allFonts(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allFonts(Spreadsheet $spreadsheet)
     {
         // Get an array of unique fonts
         $aFonts = [];
@@ -673,13 +683,13 @@ class Style extends WriterPart
     /**
      * Get an array of all borders.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\Borders[] All borders in PhpSpreadsheet
+     * @return Borders[] All borders in PhpSpreadsheet
      */
-    public function allBorders(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allBorders(Spreadsheet $spreadsheet)
     {
         // Get an array of unique borders
         $aBorders = [];
@@ -698,13 +708,13 @@ class Style extends WriterPart
     /**
      * Get an array of all number formats.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Style\NumberFormat[] All number formats in PhpSpreadsheet
+     * @return NumberFormat[] All number formats in PhpSpreadsheet
      */
-    public function allNumberFormats(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function allNumberFormats(Spreadsheet $spreadsheet)
     {
         // Get an array of unique number formats
         $aNumFmts = [];
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Theme.php b/src/PhpSpreadsheet/Writer/Xlsx/Theme.php
index 4dde8153..da3f206f 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Theme.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Theme.php
@@ -2,7 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
-/**
+/*
  * PhpSpreadsheet.
  *
  * Copyright (c) 2006 - 2016 PhpSpreadsheet
@@ -26,6 +26,8 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
  * @copyright  Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 
 /**
  * @category   PhpSpreadsheet
@@ -131,20 +133,20 @@ class Theme extends WriterPart
     /**
      * Write theme to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
      * @return string XML Output
      */
-    public function writeTheme(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    public function writeTheme(Spreadsheet $spreadsheet)
     {
         // Create XML writer
         $objWriter = null;
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -815,7 +817,7 @@ class Theme extends WriterPart
     /**
      * Write fonts to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter
+     * @param XMLWriter $objWriter
      * @param string $latinFont
      * @param array of string                $fontSet
      *
@@ -851,7 +853,7 @@ class Theme extends WriterPart
     /**
      * Write colour scheme to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter
+     * @param XMLWriter $objWriter
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Workbook.php b/src/PhpSpreadsheet/Writer/Xlsx/Workbook.php
index 16f9f73b..d21db57d 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Workbook.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Workbook.php
@@ -2,6 +2,14 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\NamedRange;
+use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Worksheet;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
+
 /**
  * Copyright (c) 2006 - 2016 PhpSpreadsheet.
  *
@@ -29,20 +37,20 @@ class Workbook extends WriterPart
     /**
      * Write workbook to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param Spreadsheet $spreadsheet
      * @param bool $recalcRequired Indicate whether formulas should be recalculated before writing
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
-    public function writeWorkbook(\PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet, $recalcRequired = false)
+    public function writeWorkbook(Spreadsheet $spreadsheet, $recalcRequired = false)
     {
         // Create XML writer
         if ($this->getParentWriter()->getUseDiskCaching()) {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
         } else {
-            $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+            $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
         }
 
         // XML header
@@ -86,11 +94,11 @@ class Workbook extends WriterPart
     /**
      * Write file version.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeFileVersion(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter)
+    private function writeFileVersion(XMLWriter $objWriter)
     {
         $objWriter->startElement('fileVersion');
         $objWriter->writeAttribute('appName', 'xl');
@@ -103,15 +111,15 @@ class Workbook extends WriterPart
     /**
      * Write WorkbookPr.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeWorkbookPr(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter)
+    private function writeWorkbookPr(XMLWriter $objWriter)
     {
         $objWriter->startElement('workbookPr');
 
-        if (\PhpOffice\PhpSpreadsheet\Shared\Date::getExcelCalendar() == \PhpOffice\PhpSpreadsheet\Shared\Date::CALENDAR_MAC_1904) {
+        if (Date::getExcelCalendar() == Date::CALENDAR_MAC_1904) {
             $objWriter->writeAttribute('date1904', '1');
         }
 
@@ -123,12 +131,12 @@ class Workbook extends WriterPart
     /**
      * Write BookViews.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeBookViews(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeBookViews(XMLWriter $objWriter, Spreadsheet $spreadsheet)
     {
         // bookViews
         $objWriter->startElement('bookViews');
@@ -154,12 +162,12 @@ class Workbook extends WriterPart
     /**
      * Write WorkbookProtection.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeWorkbookProtection(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeWorkbookProtection(XMLWriter $objWriter, Spreadsheet $spreadsheet)
     {
         if ($spreadsheet->getSecurity()->isSecurityEnabled()) {
             $objWriter->startElement('workbookProtection');
@@ -182,12 +190,12 @@ class Workbook extends WriterPart
     /**
      * Write calcPr.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param bool $recalcRequired Indicate whether formulas should be recalculated before writing
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeCalcPr(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $recalcRequired = true)
+    private function writeCalcPr(XMLWriter $objWriter, $recalcRequired = true)
     {
         $objWriter->startElement('calcPr');
 
@@ -206,12 +214,12 @@ class Workbook extends WriterPart
     /**
      * Write sheets.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheets(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeSheets(XMLWriter $objWriter, Spreadsheet $spreadsheet)
     {
         // Write sheets
         $objWriter->startElement('sheets');
@@ -233,15 +241,15 @@ class Workbook extends WriterPart
     /**
      * Write sheet.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
+     * @param XMLWriter $objWriter XML Writer
      * @param string $pSheetname Sheet name
      * @param int $pSheetId Sheet id
      * @param int $pRelId Relationship ID
      * @param string $sheetState Sheet state (visible, hidden, veryHidden)
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheet(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, $pSheetname, $pSheetId = 1, $pRelId = 1, $sheetState = 'visible')
+    private function writeSheet(XMLWriter $objWriter, $pSheetname, $pSheetId = 1, $pRelId = 1, $sheetState = 'visible')
     {
         if ($pSheetname != '') {
             // Write sheet
@@ -254,19 +262,19 @@ class Workbook extends WriterPart
             $objWriter->writeAttribute('r:id', 'rId' . $pRelId);
             $objWriter->endElement();
         } else {
-            throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid parameters passed.');
+            throw new WriterException('Invalid parameters passed.');
         }
     }
 
     /**
      * Write Defined Names.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Spreadsheet $spreadsheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefinedNames(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeDefinedNames(XMLWriter $objWriter, Spreadsheet $spreadsheet)
     {
         // Write defined names
         $objWriter->startElement('definedNames');
@@ -296,12 +304,12 @@ class Workbook extends WriterPart
     /**
      * Write named ranges.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Spreadsheet $spreadsheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeNamedRanges(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\SpreadSheet $spreadsheet)
+    private function writeNamedRanges(XMLWriter $objWriter, Spreadsheet $spreadsheet)
     {
         // Loop named ranges
         $namedRanges = $spreadsheet->getNamedRanges();
@@ -313,12 +321,12 @@ class Workbook extends WriterPart
     /**
      * Write Defined Name for named range.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\NamedRange $pNamedRange
+     * @param XMLWriter $objWriter XML Writer
+     * @param NamedRange $pNamedRange
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefinedNameForNamedRange(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\NamedRange $pNamedRange)
+    private function writeDefinedNameForNamedRange(XMLWriter $objWriter, NamedRange $pNamedRange)
     {
         // definedName for named range
         $objWriter->startElement('definedName');
@@ -328,14 +336,14 @@ class Workbook extends WriterPart
         }
 
         // Create absolute coordinate and write as raw text
-        $range = \PhpOffice\PhpSpreadsheet\Cell::splitRange($pNamedRange->getRange());
+        $range = Cell::splitRange($pNamedRange->getRange());
         for ($i = 0; $i < count($range); ++$i) {
-            $range[$i][0] = '\'' . str_replace("'", "''", $pNamedRange->getWorksheet()->getTitle()) . '\'!' . \PhpOffice\PhpSpreadsheet\Cell::absoluteReference($range[$i][0]);
+            $range[$i][0] = '\'' . str_replace("'", "''", $pNamedRange->getWorksheet()->getTitle()) . '\'!' . Cell::absoluteReference($range[$i][0]);
             if (isset($range[$i][1])) {
-                $range[$i][1] = \PhpOffice\PhpSpreadsheet\Cell::absoluteReference($range[$i][1]);
+                $range[$i][1] = Cell::absoluteReference($range[$i][1]);
             }
         }
-        $range = \PhpOffice\PhpSpreadsheet\Cell::buildRange($range);
+        $range = Cell::buildRange($range);
 
         $objWriter->writeRawData($range);
 
@@ -345,13 +353,13 @@ class Workbook extends WriterPart
     /**
      * Write Defined Name for autoFilter.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Worksheet $pSheet
      * @param int $pSheetId
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefinedNameForAutofilter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $pSheetId = 0)
+    private function writeDefinedNameForAutofilter(XMLWriter $objWriter, Worksheet $pSheet, $pSheetId = 0)
     {
         // definedName for autoFilter
         $autoFilterRange = $pSheet->getAutoFilter()->getRange();
@@ -362,15 +370,15 @@ class Workbook extends WriterPart
             $objWriter->writeAttribute('hidden', '1');
 
             // Create absolute coordinate and write as raw text
-            $range = \PhpOffice\PhpSpreadsheet\Cell::splitRange($autoFilterRange);
+            $range = Cell::splitRange($autoFilterRange);
             $range = $range[0];
             //    Strip any worksheet ref so we can make the cell ref absolute
             if (strpos($range[0], '!') !== false) {
                 list($ws, $range[0]) = explode('!', $range[0]);
             }
 
-            $range[0] = \PhpOffice\PhpSpreadsheet\Cell::absoluteCoordinate($range[0]);
-            $range[1] = \PhpOffice\PhpSpreadsheet\Cell::absoluteCoordinate($range[1]);
+            $range[0] = Cell::absoluteCoordinate($range[0]);
+            $range[1] = Cell::absoluteCoordinate($range[1]);
             $range = implode(':', $range);
 
             $objWriter->writeRawData('\'' . str_replace("'", "''", $pSheet->getTitle()) . '\'!' . $range);
@@ -382,13 +390,13 @@ class Workbook extends WriterPart
     /**
      * Write Defined Name for PrintTitles.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Worksheet $pSheet
      * @param int $pSheetId
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefinedNameForPrintTitles(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $pSheetId = 0)
+    private function writeDefinedNameForPrintTitles(XMLWriter $objWriter, Worksheet $pSheet, $pSheetId = 0)
     {
         // definedName for PrintTitles
         if ($pSheet->getPageSetup()->isColumnsToRepeatAtLeftSet() || $pSheet->getPageSetup()->isRowsToRepeatAtTopSet()) {
@@ -426,13 +434,13 @@ class Workbook extends WriterPart
     /**
      * Write Defined Name for PrintTitles.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param Worksheet $pSheet
      * @param int $pSheetId
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDefinedNameForPrintArea(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $pSheetId = 0)
+    private function writeDefinedNameForPrintArea(XMLWriter $objWriter, Worksheet $pSheet, $pSheetId = 0)
     {
         // definedName for PrintArea
         if ($pSheet->getPageSetup()->isPrintAreaSet()) {
@@ -444,12 +452,12 @@ class Workbook extends WriterPart
             $settingString = '';
 
             // Print area
-            $printArea = \PhpOffice\PhpSpreadsheet\Cell::splitRange($pSheet->getPageSetup()->getPrintArea());
+            $printArea = Cell::splitRange($pSheet->getPageSetup()->getPrintArea());
 
             $chunks = [];
             foreach ($printArea as $printAreaRect) {
-                $printAreaRect[0] = \PhpOffice\PhpSpreadsheet\Cell::absoluteReference($printAreaRect[0]);
-                $printAreaRect[1] = \PhpOffice\PhpSpreadsheet\Cell::absoluteReference($printAreaRect[1]);
+                $printAreaRect[0] = Cell::absoluteReference($printAreaRect[0]);
+                $printAreaRect[1] = Cell::absoluteReference($printAreaRect[1]);
                 $chunks[] = '\'' . str_replace("'", "''", $pSheet->getTitle()) . '\'!' . implode(':', $printAreaRect);
             }
 
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
index e8d3b715..f5bf2bf7 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
@@ -2,7 +2,7 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
-/**
+/*
  * PhpSpreadsheet.
  *
  * Copyright (c) 2006 - 2015 PhpSpreadsheet
@@ -26,6 +26,16 @@ namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
  * @copyright  Copyright (c) 2006 - 2015 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
  * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
  */
+use PhpOffice\PhpSpreadsheet\Cell;
+use PhpOffice\PhpSpreadsheet\RichText;
+use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PhpOffice\PhpSpreadsheet\Shared\XMLWriter;
+use PhpOffice\PhpSpreadsheet\Style\Conditional;
+use PhpOffice\PhpSpreadsheet\Worksheet as PhpspreadsheetWorksheet;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule;
+use PhpOffice\PhpSpreadsheet\Worksheet\SheetView;
+use PhpOffice\PhpSpreadsheet\Writer\Exception as WriterException;
 
 /**
  * @category   PhpSpreadsheet
@@ -37,11 +47,11 @@ class Worksheet extends WriterPart
     /**
      * Write worksheet to XML format.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet
+     * @param PhpspreadsheetWorksheet $pSheet
      * @param string[] $pStringTable
      * @param bool $includeCharts Flag indicating if we should write charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      *
      * @return string XML Output
      */
@@ -51,9 +61,9 @@ class Worksheet extends WriterPart
             // Create XML writer
             $objWriter = null;
             if ($this->getParentWriter()->getUseDiskCaching()) {
-                $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
+                $objWriter = new XMLWriter(XMLWriter::STORAGE_DISK, $this->getParentWriter()->getDiskCachingDirectory());
             } else {
-                $objWriter = new \PhpOffice\PhpSpreadsheet\Shared\XMLWriter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter::STORAGE_MEMORY);
+                $objWriter = new XMLWriter(XMLWriter::STORAGE_MEMORY);
             }
 
             // XML header
@@ -133,18 +143,18 @@ class Worksheet extends WriterPart
             // Return
             return $objWriter->getData();
         }
-        throw new \PhpOffice\PhpSpreadsheet\Writer\Exception('Invalid \\PhpOffice\\PhpSpreadsheet\\Worksheet object passed.');
+        throw new WriterException('Invalid \\PhpOffice\\PhpSpreadsheet\\Worksheet object passed.');
     }
 
     /**
      * Write SheetPr.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheetPr(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeSheetPr(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // sheetPr
         $objWriter->startElement('sheetPr');
@@ -187,12 +197,12 @@ class Worksheet extends WriterPart
     /**
      * Write Dimension.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDimension(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeDimension(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // dimension
         $objWriter->startElement('dimension');
@@ -203,12 +213,12 @@ class Worksheet extends WriterPart
     /**
      * Write SheetViews.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheetViews(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeSheetViews(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // sheetViews
         $objWriter->startElement('sheetViews');
@@ -233,7 +243,7 @@ class Worksheet extends WriterPart
         }
 
         // View Layout Type
-        if ($pSheet->getSheetView()->getView() !== \PhpOffice\PhpSpreadsheet\Worksheet\SheetView::SHEETVIEW_NORMAL) {
+        if ($pSheet->getSheetView()->getView() !== SheetView::SHEETVIEW_NORMAL) {
             $objWriter->writeAttribute('view', $pSheet->getSheetView()->getView());
         }
 
@@ -266,8 +276,8 @@ class Worksheet extends WriterPart
             // Calculate freeze coordinates
             $xSplit = $ySplit = 0;
 
-            list($xSplit, $ySplit) = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($topLeftCell);
-            $xSplit = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($xSplit);
+            list($xSplit, $ySplit) = Cell::coordinateFromString($topLeftCell);
+            $xSplit = Cell::columnIndexFromString($xSplit);
 
             // pane
             $pane = 'topRight';
@@ -316,12 +326,12 @@ class Worksheet extends WriterPart
     /**
      * Write SheetFormatPr.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheetFormatPr(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeSheetFormatPr(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // sheetFormatPr
         $objWriter->startElement('sheetFormatPr');
@@ -329,7 +339,7 @@ class Worksheet extends WriterPart
         // Default row height
         if ($pSheet->getDefaultRowDimension()->getRowHeight() >= 0) {
             $objWriter->writeAttribute('customHeight', 'true');
-            $objWriter->writeAttribute('defaultRowHeight', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getDefaultRowDimension()->getRowHeight()));
+            $objWriter->writeAttribute('defaultRowHeight', StringHelper::formatNumber($pSheet->getDefaultRowDimension()->getRowHeight()));
         } else {
             $objWriter->writeAttribute('defaultRowHeight', '14.4');
         }
@@ -342,7 +352,7 @@ class Worksheet extends WriterPart
 
         // Default column width
         if ($pSheet->getDefaultColumnDimension()->getWidth() >= 0) {
-            $objWriter->writeAttribute('defaultColWidth', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getDefaultColumnDimension()->getWidth()));
+            $objWriter->writeAttribute('defaultColWidth', StringHelper::formatNumber($pSheet->getDefaultColumnDimension()->getWidth()));
         }
 
         // Outline level - row
@@ -369,12 +379,12 @@ class Worksheet extends WriterPart
     /**
      * Write Cols.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeCols(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeCols(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // cols
         if (count($pSheet->getColumnDimensions()) > 0) {
@@ -386,15 +396,15 @@ class Worksheet extends WriterPart
             foreach ($pSheet->getColumnDimensions() as $colDimension) {
                 // col
                 $objWriter->startElement('col');
-                $objWriter->writeAttribute('min', \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colDimension->getColumnIndex()));
-                $objWriter->writeAttribute('max', \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($colDimension->getColumnIndex()));
+                $objWriter->writeAttribute('min', Cell::columnIndexFromString($colDimension->getColumnIndex()));
+                $objWriter->writeAttribute('max', Cell::columnIndexFromString($colDimension->getColumnIndex()));
 
                 if ($colDimension->getWidth() < 0) {
                     // No width set, apply default of 10
                     $objWriter->writeAttribute('width', '9.10');
                 } else {
                     // Width set
-                    $objWriter->writeAttribute('width', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($colDimension->getWidth()));
+                    $objWriter->writeAttribute('width', StringHelper::formatNumber($colDimension->getWidth()));
                 }
 
                 // Column visibility
@@ -435,12 +445,12 @@ class Worksheet extends WriterPart
     /**
      * Write SheetProtection.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheetProtection(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeSheetProtection(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // sheetProtection
         $objWriter->startElement('sheetProtection');
@@ -471,12 +481,12 @@ class Worksheet extends WriterPart
     /**
      * Write ConditionalFormatting.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeConditionalFormatting(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeConditionalFormatting(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // Conditional id
         $id = 1;
@@ -488,7 +498,7 @@ class Worksheet extends WriterPart
                 // if ($this->getParentWriter()->getStylesConditionalHashTable()->getIndexForHashCode($conditional->getHashCode()) == '') {
                 //    continue;
                 // }
-                if ($conditional->getConditionType() != \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_NONE) {
+                if ($conditional->getConditionType() != Conditional::CONDITION_NONE) {
                     // conditionalFormatting
                     $objWriter->startElement('conditionalFormatting');
                     $objWriter->writeAttribute('sqref', $cellCoordinate);
@@ -499,35 +509,35 @@ class Worksheet extends WriterPart
                     $objWriter->writeAttribute('dxfId', $this->getParentWriter()->getStylesConditionalHashTable()->getIndexForHashCode($conditional->getHashCode()));
                     $objWriter->writeAttribute('priority', $id++);
 
-                    if (($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS || $conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT)
-                        && $conditional->getOperatorType() != \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_NONE) {
+                    if (($conditional->getConditionType() == Conditional::CONDITION_CELLIS || $conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT)
+                        && $conditional->getOperatorType() != Conditional::OPERATOR_NONE) {
                         $objWriter->writeAttribute('operator', $conditional->getOperatorType());
                     }
 
-                    if ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
+                    if ($conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
                         && !is_null($conditional->getText())) {
                         $objWriter->writeAttribute('text', $conditional->getText());
                     }
 
-                    if ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
-                        && $conditional->getOperatorType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_CONTAINSTEXT
+                    if ($conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
+                        && $conditional->getOperatorType() == Conditional::OPERATOR_CONTAINSTEXT
                         && !is_null($conditional->getText())) {
                         $objWriter->writeElement('formula', 'NOT(ISERROR(SEARCH("' . $conditional->getText() . '",' . $cellCoordinate . ')))');
-                    } elseif ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
-                        && $conditional->getOperatorType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_BEGINSWITH
+                    } elseif ($conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
+                        && $conditional->getOperatorType() == Conditional::OPERATOR_BEGINSWITH
                         && !is_null($conditional->getText())) {
                         $objWriter->writeElement('formula', 'LEFT(' . $cellCoordinate . ',' . strlen($conditional->getText()) . ')="' . $conditional->getText() . '"');
-                    } elseif ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
-                        && $conditional->getOperatorType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_ENDSWITH
+                    } elseif ($conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
+                        && $conditional->getOperatorType() == Conditional::OPERATOR_ENDSWITH
                         && !is_null($conditional->getText())) {
                         $objWriter->writeElement('formula', 'RIGHT(' . $cellCoordinate . ',' . strlen($conditional->getText()) . ')="' . $conditional->getText() . '"');
-                    } elseif ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
-                        && $conditional->getOperatorType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::OPERATOR_NOTCONTAINS
+                    } elseif ($conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
+                        && $conditional->getOperatorType() == Conditional::OPERATOR_NOTCONTAINS
                         && !is_null($conditional->getText())) {
                         $objWriter->writeElement('formula', 'ISERROR(SEARCH("' . $conditional->getText() . '",' . $cellCoordinate . '))');
-                    } elseif ($conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CELLIS
-                        || $conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_CONTAINSTEXT
-                        || $conditional->getConditionType() == \PhpOffice\PhpSpreadsheet\Style\Conditional::CONDITION_EXPRESSION) {
+                    } elseif ($conditional->getConditionType() == Conditional::CONDITION_CELLIS
+                        || $conditional->getConditionType() == Conditional::CONDITION_CONTAINSTEXT
+                        || $conditional->getConditionType() == Conditional::CONDITION_EXPRESSION) {
                         foreach ($conditional->getConditions() as $formula) {
                             // Formula
                             $objWriter->writeElement('formula', $formula);
@@ -545,12 +555,12 @@ class Worksheet extends WriterPart
     /**
      * Write DataValidations.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDataValidations(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeDataValidations(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // Datavalidation collection
         $dataValidationCollection = $pSheet->getDataValidationCollection();
@@ -612,12 +622,12 @@ class Worksheet extends WriterPart
     /**
      * Write Hyperlinks.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeHyperlinks(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeHyperlinks(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // Hyperlink collection
         $hyperlinkCollection = $pSheet->getHyperlinkCollection();
@@ -654,12 +664,12 @@ class Worksheet extends WriterPart
     /**
      * Write ProtectedRanges.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeProtectedRanges(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeProtectedRanges(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         if (count($pSheet->getProtectedCells()) > 0) {
             // protectedRanges
@@ -684,12 +694,12 @@ class Worksheet extends WriterPart
     /**
      * Write MergeCells.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeMergeCells(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeMergeCells(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         if (count($pSheet->getMergeCells()) > 0) {
             // mergeCells
@@ -710,12 +720,12 @@ class Worksheet extends WriterPart
     /**
      * Write PrintOptions.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writePrintOptions(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writePrintOptions(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // printOptions
         $objWriter->startElement('printOptions');
@@ -737,33 +747,33 @@ class Worksheet extends WriterPart
     /**
      * Write PageMargins.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writePageMargins(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writePageMargins(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // pageMargins
         $objWriter->startElement('pageMargins');
-        $objWriter->writeAttribute('left', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getLeft()));
-        $objWriter->writeAttribute('right', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getRight()));
-        $objWriter->writeAttribute('top', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getTop()));
-        $objWriter->writeAttribute('bottom', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getBottom()));
-        $objWriter->writeAttribute('header', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getHeader()));
-        $objWriter->writeAttribute('footer', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($pSheet->getPageMargins()->getFooter()));
+        $objWriter->writeAttribute('left', StringHelper::formatNumber($pSheet->getPageMargins()->getLeft()));
+        $objWriter->writeAttribute('right', StringHelper::formatNumber($pSheet->getPageMargins()->getRight()));
+        $objWriter->writeAttribute('top', StringHelper::formatNumber($pSheet->getPageMargins()->getTop()));
+        $objWriter->writeAttribute('bottom', StringHelper::formatNumber($pSheet->getPageMargins()->getBottom()));
+        $objWriter->writeAttribute('header', StringHelper::formatNumber($pSheet->getPageMargins()->getHeader()));
+        $objWriter->writeAttribute('footer', StringHelper::formatNumber($pSheet->getPageMargins()->getFooter()));
         $objWriter->endElement();
     }
 
     /**
      * Write AutoFilter.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeAutoFilter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeAutoFilter(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         $autoFilterRange = $pSheet->getAutoFilter()->getRange();
         if (!empty($autoFilterRange)) {
@@ -771,7 +781,7 @@ class Worksheet extends WriterPart
             $objWriter->startElement('autoFilter');
 
             // Strip any worksheet reference from the filter coordinates
-            $range = \PhpOffice\PhpSpreadsheet\Cell::splitRange($autoFilterRange);
+            $range = Cell::splitRange($autoFilterRange);
             $range = $range[0];
             //    Strip any worksheet ref
             if (strpos($range[0], '!') !== false) {
@@ -790,17 +800,17 @@ class Worksheet extends WriterPart
                         $objWriter->writeAttribute('colId', $pSheet->getAutoFilter()->getColumnOffset($columnID));
 
                         $objWriter->startElement($column->getFilterType());
-                        if ($column->getJoin() == \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND) {
+                        if ($column->getJoin() == Column::AUTOFILTER_COLUMN_JOIN_AND) {
                             $objWriter->writeAttribute('and', 1);
                         }
 
                         foreach ($rules as $rule) {
-                            if (($column->getFilterType() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER) &&
-                                ($rule->getOperator() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL) &&
+                            if (($column->getFilterType() === Column::AUTOFILTER_FILTERTYPE_FILTER) &&
+                                ($rule->getOperator() === Rule::AUTOFILTER_COLUMN_RULE_EQUAL) &&
                                 ($rule->getValue() === '')) {
                                 //    Filter rule for Blanks
                                 $objWriter->writeAttribute('blank', 1);
-                            } elseif ($rule->getRuleType() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DYNAMICFILTER) {
+                            } elseif ($rule->getRuleType() === Rule::AUTOFILTER_RULETYPE_DYNAMICFILTER) {
                                 //    Dynamic Filter Rule
                                 $objWriter->writeAttribute('type', $rule->getGrouping());
                                 $val = $column->getAttribute('val');
@@ -811,19 +821,19 @@ class Worksheet extends WriterPart
                                 if ($maxVal !== null) {
                                     $objWriter->writeAttribute('maxVal', $maxVal);
                                 }
-                            } elseif ($rule->getRuleType() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_TOPTENFILTER) {
+                            } elseif ($rule->getRuleType() === Rule::AUTOFILTER_RULETYPE_TOPTENFILTER) {
                                 //    Top 10 Filter Rule
                                 $objWriter->writeAttribute('val', $rule->getValue());
-                                $objWriter->writeAttribute('percent', (($rule->getOperator() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_TOPTEN_PERCENT) ? '1' : '0'));
-                                $objWriter->writeAttribute('top', (($rule->getGrouping() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_TOPTEN_TOP) ? '1' : '0'));
+                                $objWriter->writeAttribute('percent', (($rule->getOperator() === Rule::AUTOFILTER_COLUMN_RULE_TOPTEN_PERCENT) ? '1' : '0'));
+                                $objWriter->writeAttribute('top', (($rule->getGrouping() === Rule::AUTOFILTER_COLUMN_RULE_TOPTEN_TOP) ? '1' : '0'));
                             } else {
                                 //    Filter, DateGroupItem or CustomFilter
                                 $objWriter->startElement($rule->getRuleType());
 
-                                if ($rule->getOperator() !== \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL) {
+                                if ($rule->getOperator() !== Rule::AUTOFILTER_COLUMN_RULE_EQUAL) {
                                     $objWriter->writeAttribute('operator', $rule->getOperator());
                                 }
-                                if ($rule->getRuleType() === \PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP) {
+                                if ($rule->getRuleType() === Rule::AUTOFILTER_RULETYPE_DATEGROUP) {
                                     // Date Group filters
                                     foreach ($rule->getValue() as $key => $value) {
                                         if ($value > '') {
@@ -852,12 +862,12 @@ class Worksheet extends WriterPart
     /**
      * Write PageSetup.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writePageSetup(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writePageSetup(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // pageSetup
         $objWriter->startElement('pageSetup');
@@ -888,12 +898,12 @@ class Worksheet extends WriterPart
     /**
      * Write Header / Footer.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeHeaderFooter(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeHeaderFooter(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // headerFooter
         $objWriter->startElement('headerFooter');
@@ -914,20 +924,20 @@ class Worksheet extends WriterPart
     /**
      * Write Breaks.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeBreaks(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeBreaks(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // Get row and column breaks
         $aRowBreaks = [];
         $aColumnBreaks = [];
         foreach ($pSheet->getBreaks() as $cell => $breakType) {
-            if ($breakType == \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_ROW) {
+            if ($breakType == PhpspreadsheetWorksheet::BREAK_ROW) {
                 $aRowBreaks[] = $cell;
-            } elseif ($breakType == \PhpOffice\PhpSpreadsheet\Worksheet::BREAK_COLUMN) {
+            } elseif ($breakType == PhpspreadsheetWorksheet::BREAK_COLUMN) {
                 $aColumnBreaks[] = $cell;
             }
         }
@@ -939,7 +949,7 @@ class Worksheet extends WriterPart
             $objWriter->writeAttribute('manualBreakCount', count($aRowBreaks));
 
             foreach ($aRowBreaks as $cell) {
-                $coords = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($cell);
+                $coords = Cell::coordinateFromString($cell);
 
                 $objWriter->startElement('brk');
                 $objWriter->writeAttribute('id', $coords[1]);
@@ -957,10 +967,10 @@ class Worksheet extends WriterPart
             $objWriter->writeAttribute('manualBreakCount', count($aColumnBreaks));
 
             foreach ($aColumnBreaks as $cell) {
-                $coords = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($cell);
+                $coords = Cell::coordinateFromString($cell);
 
                 $objWriter->startElement('brk');
-                $objWriter->writeAttribute('id', \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($coords[0]) - 1);
+                $objWriter->writeAttribute('id', Cell::columnIndexFromString($coords[0]) - 1);
                 $objWriter->writeAttribute('man', '1');
                 $objWriter->endElement();
             }
@@ -972,13 +982,13 @@ class Worksheet extends WriterPart
     /**
      * Write SheetData.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      * @param string[] $pStringTable String table
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeSheetData(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, array $pStringTable)
+    private function writeSheetData(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet, array $pStringTable)
     {
         // Flipped stringtable, for faster index searching
         $aFlippedStringTable = $this->getParentWriter()->getWriterPart('stringtable')->flipStringTable($pStringTable);
@@ -987,7 +997,7 @@ class Worksheet extends WriterPart
         $objWriter->startElement('sheetData');
 
         // Get column count
-        $colCount = \PhpOffice\PhpSpreadsheet\Cell::columnIndexFromString($pSheet->getHighestColumn());
+        $colCount = Cell::columnIndexFromString($pSheet->getHighestColumn());
 
         // Highest row number
         $highestRow = $pSheet->getHighestRow();
@@ -995,7 +1005,7 @@ class Worksheet extends WriterPart
         // Loop through cells
         $cellsByRow = [];
         foreach ($pSheet->getCoordinates() as $coordinate) {
-            $cellAddress = \PhpOffice\PhpSpreadsheet\Cell::coordinateFromString($coordinate);
+            $cellAddress = Cell::coordinateFromString($coordinate);
             $cellsByRow[$cellAddress[1]][] = $coordinate;
         }
 
@@ -1016,7 +1026,7 @@ class Worksheet extends WriterPart
                 // Row dimensions
                 if ($rowDimension->getRowHeight() >= 0) {
                     $objWriter->writeAttribute('customHeight', '1');
-                    $objWriter->writeAttribute('ht', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($rowDimension->getRowHeight()));
+                    $objWriter->writeAttribute('ht', StringHelper::formatNumber($rowDimension->getRowHeight()));
                 }
 
                 // Row visibility
@@ -1059,15 +1069,15 @@ class Worksheet extends WriterPart
     /**
      * Write Cell.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
-     * @param \PhpOffice\PhpSpreadsheet\Cell $pCellAddress Cell Address
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
+     * @param Cell $pCellAddress Cell Address
      * @param string[] $pStringTable String table
      * @param string[] $pFlippedStringTable String table (flipped), for faster index searching
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeCell(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet, $pCellAddress, array $pFlippedStringTable)
+    private function writeCell(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet, $pCellAddress, array $pFlippedStringTable)
     {
         // Cell
         $pCell = $pSheet->getCell($pCellAddress);
@@ -1106,9 +1116,9 @@ class Worksheet extends WriterPart
             // Write data depending on its type
             switch (strtolower($mappedType)) {
                 case 'inlinestr':    // Inline string
-                    if (!$cellValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
-                        $objWriter->writeElement('t', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::controlCharacterPHP2OOXML(htmlspecialchars($cellValue)));
-                    } elseif ($cellValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+                    if (!$cellValue instanceof RichText) {
+                        $objWriter->writeElement('t', StringHelper::controlCharacterPHP2OOXML(htmlspecialchars($cellValue)));
+                    } elseif ($cellValue instanceof RichText) {
                         $objWriter->startElement('is');
                         $this->getParentWriter()->getWriterPart('stringtable')->writeRichText($objWriter, $cellValue);
                         $objWriter->endElement();
@@ -1116,11 +1126,11 @@ class Worksheet extends WriterPart
 
                     break;
                 case 's':            // String
-                    if (!$cellValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+                    if (!$cellValue instanceof RichText) {
                         if (isset($pFlippedStringTable[$cellValue])) {
                             $objWriter->writeElement('v', $pFlippedStringTable[$cellValue]);
                         }
-                    } elseif ($cellValue instanceof \PhpOffice\PhpSpreadsheet\RichText) {
+                    } elseif ($cellValue instanceof RichText) {
                         $objWriter->writeElement('v', $pFlippedStringTable[$cellValue->getHashCode()]);
                     }
 
@@ -1141,7 +1151,7 @@ class Worksheet extends WriterPart
                     if ($this->getParentWriter()->getOffice2003Compatibility() === false) {
                         if ($this->getParentWriter()->getPreCalculateFormulas()) {
                             if (!is_array($calculatedValue) && substr($calculatedValue, 0, 1) != '#') {
-                                $objWriter->writeElement('v', \PhpOffice\PhpSpreadsheet\Shared\StringHelper::formatNumber($calculatedValue));
+                                $objWriter->writeElement('v', StringHelper::formatNumber($calculatedValue));
                             } else {
                                 $objWriter->writeElement('v', '0');
                             }
@@ -1175,13 +1185,13 @@ class Worksheet extends WriterPart
     /**
      * Write Drawings.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      * @param bool $includeCharts Flag indicating if we should include drawing details for charts
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeDrawings(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter = null, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet = null, $includeCharts = false)
+    private function writeDrawings(XMLWriter $objWriter = null, PhpspreadsheetWorksheet $pSheet = null, $includeCharts = false)
     {
         $chartCount = ($includeCharts) ? $pSheet->getChartCollection()->count() : 0;
         // If sheet contains drawings, add the relationships
@@ -1196,12 +1206,12 @@ class Worksheet extends WriterPart
     /**
      * Write LegacyDrawing.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeLegacyDrawing(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeLegacyDrawing(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // If sheet contains comments, add the relationships
         if (count($pSheet->getComments()) > 0) {
@@ -1214,12 +1224,12 @@ class Worksheet extends WriterPart
     /**
      * Write LegacyDrawingHF.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter XML Writer
-     * @param \PhpOffice\PhpSpreadsheet\Worksheet $pSheet Worksheet
+     * @param XMLWriter $objWriter XML Writer
+     * @param PhpspreadsheetWorksheet $pSheet Worksheet
      *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
+     * @throws WriterException
      */
-    private function writeLegacyDrawingHF(\PhpOffice\PhpSpreadsheet\Shared\XMLWriter $objWriter, \PhpOffice\PhpSpreadsheet\Worksheet $pSheet)
+    private function writeLegacyDrawingHF(XMLWriter $objWriter, PhpspreadsheetWorksheet $pSheet)
     {
         // If sheet contains images, add the relationships
         if (count($pSheet->getHeaderFooter()->getImages()) > 0) {
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/WriterPart.php b/src/PhpSpreadsheet/Writer/Xlsx/WriterPart.php
index a743ab12..e6a16fda 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/WriterPart.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/WriterPart.php
@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Writer\Xlsx;
 
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
+
 /**
  * Copyright (c) 2006 - 2015 PhpSpreadsheet.
  *
@@ -29,7 +31,7 @@ abstract class WriterPart
     /**
      * Parent Xlsx object.
      *
-     * @var \PhpOffice\PhpSpreadsheet\Writer\Xlsx
+     * @var Xlsx
      */
     private $parentWriter;
 
@@ -38,7 +40,7 @@ abstract class WriterPart
      *
      * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
      *
-     * @return \PhpOffice\PhpSpreadsheet\Writer\Xlsx
+     * @return Xlsx
      */
     public function getParentWriter()
     {
@@ -48,9 +50,9 @@ abstract class WriterPart
     /**
      * Set parent Xlsx object.
      *
-     * @param \PhpOffice\PhpSpreadsheet\Writer\Xlsx $pWriter
+     * @param Xlsx $pWriter
      */
-    public function __construct(\PhpOffice\PhpSpreadsheet\Writer\Xlsx $pWriter)
+    public function __construct(Xlsx $pWriter)
     {
         $this->parentWriter = $pWriter;
     }
diff --git a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
index d8458045..6b05d454 100644
--- a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
@@ -5,11 +5,12 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 use PhpOffice\PhpSpreadsheet\Calculation\DateTime;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PHPUnit_Framework_TestCase;
 
 /**
  * Class DateTimeTest.
  */
-class DateTimeTest extends \PHPUnit_Framework_TestCase
+class DateTimeTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/EngineeringTest.php b/tests/PhpSpreadsheetTests/Calculation/EngineeringTest.php
index 89d1e5f1..2e19eff7 100644
--- a/tests/PhpSpreadsheetTests/Calculation/EngineeringTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/EngineeringTest.php
@@ -4,17 +4,19 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Engineering;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PhpOffice\PhpSpreadsheetTests\Custom\ComplexAssert;
+use PHPUnit_Framework_TestCase;
 
-class EngineeringTest extends \PHPUnit_Framework_TestCase
+class EngineeringTest extends PHPUnit_Framework_TestCase
 {
     /**
-     * @var \PhpOffice\PhpSpreadsheetTests\Custom\ComplexAssert
+     * @var ComplexAssert
      */
     protected $complexAssert;
 
     public function setUp()
     {
-        $this->complexAssert = new \PhpOffice\PhpSpreadsheetTests\Custom\ComplexAssert();
+        $this->complexAssert = new ComplexAssert();
         Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
diff --git a/tests/PhpSpreadsheetTests/Calculation/FinancialTest.php b/tests/PhpSpreadsheetTests/Calculation/FinancialTest.php
index b61ef6ae..04f6b4e8 100644
--- a/tests/PhpSpreadsheetTests/Calculation/FinancialTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/FinancialTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Financial;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PHPUnit_Framework_TestCase;
 
-class FinancialTest extends \PHPUnit_Framework_TestCase
+class FinancialTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/FunctionsTest.php b/tests/PhpSpreadsheetTests/Calculation/FunctionsTest.php
index 2f6aaa06..371f2826 100644
--- a/tests/PhpSpreadsheetTests/Calculation/FunctionsTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/FunctionsTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PHPUnit_Framework_TestCase;
 
-class FunctionsTest extends \PHPUnit_Framework_TestCase
+class FunctionsTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/LogicalTest.php b/tests/PhpSpreadsheetTests/Calculation/LogicalTest.php
index ab9cf4fd..d1aac26a 100644
--- a/tests/PhpSpreadsheetTests/Calculation/LogicalTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/LogicalTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Calculation\Logical;
+use PHPUnit_Framework_TestCase;
 
-class LogicalTest extends \PHPUnit_Framework_TestCase
+class LogicalTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/LookupRefTest.php b/tests/PhpSpreadsheetTests/Calculation/LookupRefTest.php
index 39dfa17d..94696e4c 100644
--- a/tests/PhpSpreadsheetTests/Calculation/LookupRefTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/LookupRefTest.php
@@ -4,11 +4,12 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Calculation\LookupRef;
+use PHPUnit_Framework_TestCase;
 
 /**
  * Class LookupRefTest.
  */
-class LookupRefTest extends \PHPUnit_Framework_TestCase
+class LookupRefTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php b/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
index 518250fa..d765931c 100644
--- a/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/MathTrigTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 use PhpOffice\PhpSpreadsheet\Calculation;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Calculation\MathTrig;
+use PHPUnit_Framework_TestCase;
 
-class MathTrigTest extends \PHPUnit_Framework_TestCase
+class MathTrigTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Calculation/TextDataTest.php b/tests/PhpSpreadsheetTests/Calculation/TextDataTest.php
index e4c06b2d..8a6cd0c5 100644
--- a/tests/PhpSpreadsheetTests/Calculation/TextDataTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/TextDataTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Calculation;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
 use PhpOffice\PhpSpreadsheet\Calculation\TextData;
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PHPUnit_Framework_TestCase;
 
-class TextDataTest extends \PHPUnit_Framework_TestCase
+class TextDataTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/CalculationTest.php b/tests/PhpSpreadsheetTests/CalculationTest.php
index 8711e6ac..d8979979 100644
--- a/tests/PhpSpreadsheetTests/CalculationTest.php
+++ b/tests/PhpSpreadsheetTests/CalculationTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests;
 
 use PhpOffice\PhpSpreadsheet\Calculation;
 use PhpOffice\PhpSpreadsheet\Calculation\Functions;
+use PHPUnit_Framework_TestCase;
 
-class CalculationTest extends \PHPUnit_Framework_TestCase
+class CalculationTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Cell/AdvancedValueBinderTest.php b/tests/PhpSpreadsheetTests/Cell/AdvancedValueBinderTest.php
index 2f8b29a3..637ced24 100644
--- a/tests/PhpSpreadsheetTests/Cell/AdvancedValueBinderTest.php
+++ b/tests/PhpSpreadsheetTests/Cell/AdvancedValueBinderTest.php
@@ -9,8 +9,9 @@ use PhpOffice\PhpSpreadsheet\Collection\Cells;
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use PhpOffice\PhpSpreadsheet\Worksheet;
+use PHPUnit_Framework_TestCase;
 
-class AdvancedValueBinderTest extends \PHPUnit_Framework_TestCase
+class AdvancedValueBinderTest extends PHPUnit_Framework_TestCase
 {
     public function provider()
     {
diff --git a/tests/PhpSpreadsheetTests/Cell/DataTypeTest.php b/tests/PhpSpreadsheetTests/Cell/DataTypeTest.php
index f98f4fb5..92ab1f29 100644
--- a/tests/PhpSpreadsheetTests/Cell/DataTypeTest.php
+++ b/tests/PhpSpreadsheetTests/Cell/DataTypeTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Cell;
 
 use PhpOffice\PhpSpreadsheet\Cell\DataType;
+use PHPUnit_Framework_TestCase;
 
-class DataTypeTest extends \PHPUnit_Framework_TestCase
+class DataTypeTest extends PHPUnit_Framework_TestCase
 {
     public function testGetErrorCodes()
     {
diff --git a/tests/PhpSpreadsheetTests/Cell/DefaultValueBinderTest.php b/tests/PhpSpreadsheetTests/Cell/DefaultValueBinderTest.php
index ca892d66..4d09a56a 100644
--- a/tests/PhpSpreadsheetTests/Cell/DefaultValueBinderTest.php
+++ b/tests/PhpSpreadsheetTests/Cell/DefaultValueBinderTest.php
@@ -2,12 +2,14 @@
 
 namespace PhpOffice\PhpSpreadsheetTests\Cell;
 
+use DateTime;
 use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Cell\DataType;
 use PhpOffice\PhpSpreadsheet\Cell\DefaultValueBinder;
 use PhpOffice\PhpSpreadsheet\RichText;
+use PHPUnit_Framework_TestCase;
 
-class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
+class DefaultValueBinderTest extends PHPUnit_Framework_TestCase
 {
     protected $cellStub;
 
@@ -50,7 +52,7 @@ class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
             ['123'],
             ['-123.456'],
             ['#REF!'],
-            [new \DateTime()],
+            [new DateTime()],
         ];
     }
 
diff --git a/tests/PhpSpreadsheetTests/Cell/HyperlinkTest.php b/tests/PhpSpreadsheetTests/Cell/HyperlinkTest.php
index b4c68f62..3d86cb62 100644
--- a/tests/PhpSpreadsheetTests/Cell/HyperlinkTest.php
+++ b/tests/PhpSpreadsheetTests/Cell/HyperlinkTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Cell;
 
 use PhpOffice\PhpSpreadsheet\Cell\Hyperlink;
+use PHPUnit_Framework_TestCase;
 
-class HyperlinkTest extends \PHPUnit_Framework_TestCase
+class HyperlinkTest extends PHPUnit_Framework_TestCase
 {
     public function testGetUrl()
     {
diff --git a/tests/PhpSpreadsheetTests/CellTest.php b/tests/PhpSpreadsheetTests/CellTest.php
index 6e60efe5..118978f9 100644
--- a/tests/PhpSpreadsheetTests/CellTest.php
+++ b/tests/PhpSpreadsheetTests/CellTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests;
 
 use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Exception;
+use PHPUnit_Framework_TestCase;
 
-class CellTest extends \PHPUnit_Framework_TestCase
+class CellTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerColumnString
diff --git a/tests/PhpSpreadsheetTests/Chart/DataSeriesValuesTest.php b/tests/PhpSpreadsheetTests/Chart/DataSeriesValuesTest.php
index 7e87bfab..a7746b16 100644
--- a/tests/PhpSpreadsheetTests/Chart/DataSeriesValuesTest.php
+++ b/tests/PhpSpreadsheetTests/Chart/DataSeriesValuesTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Chart;
 
 use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
 use PhpOffice\PhpSpreadsheet\Exception;
+use PHPUnit_Framework_TestCase;
 
-class DataSeriesValuesTest extends \PHPUnit_Framework_TestCase
+class DataSeriesValuesTest extends PHPUnit_Framework_TestCase
 {
     public function testSetDataType()
     {
diff --git a/tests/PhpSpreadsheetTests/Chart/LayoutTest.php b/tests/PhpSpreadsheetTests/Chart/LayoutTest.php
index de8d3c9f..22daa18d 100644
--- a/tests/PhpSpreadsheetTests/Chart/LayoutTest.php
+++ b/tests/PhpSpreadsheetTests/Chart/LayoutTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Chart;
 
 use PhpOffice\PhpSpreadsheet\Chart\Layout;
+use PHPUnit_Framework_TestCase;
 
-class LayoutTest extends \PHPUnit_Framework_TestCase
+class LayoutTest extends PHPUnit_Framework_TestCase
 {
     public function testSetLayoutTarget()
     {
diff --git a/tests/PhpSpreadsheetTests/Chart/LegendTest.php b/tests/PhpSpreadsheetTests/Chart/LegendTest.php
index e472fbfe..1df0ab70 100644
--- a/tests/PhpSpreadsheetTests/Chart/LegendTest.php
+++ b/tests/PhpSpreadsheetTests/Chart/LegendTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Chart;
 
 use PhpOffice\PhpSpreadsheet\Chart\Legend;
+use PHPUnit_Framework_TestCase;
 
-class LegendTest extends \PHPUnit_Framework_TestCase
+class LegendTest extends PHPUnit_Framework_TestCase
 {
     public function testSetPosition()
     {
diff --git a/tests/PhpSpreadsheetTests/Collection/CellsTest.php b/tests/PhpSpreadsheetTests/Collection/CellsTest.php
index 6b91ec6f..33899be7 100644
--- a/tests/PhpSpreadsheetTests/Collection/CellsTest.php
+++ b/tests/PhpSpreadsheetTests/Collection/CellsTest.php
@@ -7,8 +7,9 @@ use PhpOffice\PhpSpreadsheet\Collection\Cells;
 use PhpOffice\PhpSpreadsheet\Collection\Memory;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Worksheet;
+use PHPUnit_Framework_TestCase;
 
-class CellsTest extends \PHPUnit_Framework_TestCase
+class CellsTest extends PHPUnit_Framework_TestCase
 {
     public function testCollectionCell()
     {
diff --git a/tests/PhpSpreadsheetTests/Helper/MigratorTest.php b/tests/PhpSpreadsheetTests/Helper/MigratorTest.php
index 39a922ab..cb91f65a 100644
--- a/tests/PhpSpreadsheetTests/Helper/MigratorTest.php
+++ b/tests/PhpSpreadsheetTests/Helper/MigratorTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Helper;
 
 use PhpOffice\PhpSpreadsheet\Helper\Migrator;
+use PHPUnit_Framework_TestCase;
 
-class MigratorTest extends \PHPUnit_Framework_TestCase
+class MigratorTest extends PHPUnit_Framework_TestCase
 {
     public function testMappingOnlyContainExistingClasses()
     {
diff --git a/tests/PhpSpreadsheetTests/IOFactoryTest.php b/tests/PhpSpreadsheetTests/IOFactoryTest.php
index 51787521..071e4bb6 100644
--- a/tests/PhpSpreadsheetTests/IOFactoryTest.php
+++ b/tests/PhpSpreadsheetTests/IOFactoryTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests;
 
 use PhpOffice\PhpSpreadsheet\IOFactory;
+use PHPUnit_Framework_TestCase;
 
-class IOFactoryTest extends \PHPUnit_Framework_TestCase
+class IOFactoryTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerIdentify
diff --git a/tests/PhpSpreadsheetTests/Reader/CsvTest.php b/tests/PhpSpreadsheetTests/Reader/CsvTest.php
index 6727b10b..90e94a52 100644
--- a/tests/PhpSpreadsheetTests/Reader/CsvTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/CsvTest.php
@@ -2,10 +2,13 @@
 
 namespace PhpOffice\PhpSpreadsheetTests\Reader;
 
+use PhpOffice\PhpSpreadsheet\Reader\Csv as ReaderCsv;
 use PhpOffice\PhpSpreadsheet\Shared\File;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Csv as WriterCsv;
+use PHPUnit_Framework_TestCase;
 
-class CsvTest extends \PHPUnit_Framework_TestCase
+class CsvTest extends PHPUnit_Framework_TestCase
 {
     public function testEnclosure()
     {
@@ -15,11 +18,11 @@ class CsvTest extends \PHPUnit_Framework_TestCase
         // Write temp file with value
         $spreadsheet = new Spreadsheet();
         $spreadsheet->getActiveSheet()->getCell('A1')->setValue($value);
-        $writer = new \PhpOffice\PhpSpreadsheet\Writer\Csv($spreadsheet);
+        $writer = new WriterCsv($spreadsheet);
         $writer->save($filename);
 
         // Read written file
-        $reader = new \PhpOffice\PhpSpreadsheet\Reader\Csv();
+        $reader = new ReaderCsv();
         $reloadedSpreadsheet = $reader->load($filename);
         $actual = $reloadedSpreadsheet->getActiveSheet()->getCell('A1')->getCalculatedValue();
         $this->assertSame($value, $actual, 'should be able to write and read strings with multiples quotes');
@@ -27,7 +30,7 @@ class CsvTest extends \PHPUnit_Framework_TestCase
 
     public function testDelimiterDetection()
     {
-        $reader = new \PhpOffice\PhpSpreadsheet\Reader\Csv();
+        $reader = new ReaderCsv();
         $this->assertNull($reader->getDelimiter());
 
         $filename = __DIR__ . '/../../data/Reader/CSV/semicolon_separated.csv';
diff --git a/tests/PhpSpreadsheetTests/Reader/HTMLTest.php b/tests/PhpSpreadsheetTests/Reader/HTMLTest.php
index 03ad95f9..b1b51a59 100644
--- a/tests/PhpSpreadsheetTests/Reader/HTMLTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/HTMLTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Reader;
 
 use PhpOffice\PhpSpreadsheet\Reader\Html;
+use PHPUnit_Framework_TestCase;
 
-class HTMLTest extends \PHPUnit_Framework_TestCase
+class HTMLTest extends PHPUnit_Framework_TestCase
 {
     public function testCsvWithAngleBracket()
     {
diff --git a/tests/PhpSpreadsheetTests/Reader/OdsTest.php b/tests/PhpSpreadsheetTests/Reader/OdsTest.php
index ccda9958..658869b0 100644
--- a/tests/PhpSpreadsheetTests/Reader/OdsTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/OdsTest.php
@@ -4,25 +4,27 @@ namespace PhpOffice\PhpSpreadsheetTests\Reader;
 
 use PhpOffice\PhpSpreadsheet\Cell\DataType;
 use PhpOffice\PhpSpreadsheet\Reader\Ods;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Style\Font;
+use PHPUnit_Framework_TestCase;
 
 /**
  * @todo The class doesn't read the bold/italic/underline properties (rich text)
  */
-class OdsTest extends \PHPUnit_Framework_TestCase
+class OdsTest extends PHPUnit_Framework_TestCase
 {
     /**
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheetOOCalcTest;
 
     /**
-     * @var \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @var Spreadsheet
      */
     private $spreadsheetData;
 
     /**
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     protected function loadOOCalcTestFile()
     {
@@ -31,14 +33,14 @@ class OdsTest extends \PHPUnit_Framework_TestCase
 
             // Load into this instance
             $reader = new Ods();
-            $this->spreadsheetOOCalcTest = $reader->loadIntoExisting($filename, new \PhpOffice\PhpSpreadsheet\Spreadsheet());
+            $this->spreadsheetOOCalcTest = $reader->loadIntoExisting($filename, new Spreadsheet());
         }
 
         return $this->spreadsheetOOCalcTest;
     }
 
     /**
-     * @return \PhpOffice\PhpSpreadsheet\Spreadsheet
+     * @return Spreadsheet
      */
     protected function loadDataFile()
     {
@@ -47,7 +49,7 @@ class OdsTest extends \PHPUnit_Framework_TestCase
 
             // Load into this instance
             $reader = new Ods();
-            $this->spreadsheetData = $reader->loadIntoExisting($filename, new \PhpOffice\PhpSpreadsheet\Spreadsheet());
+            $this->spreadsheetData = $reader->loadIntoExisting($filename, new Spreadsheet());
         }
 
         return $this->spreadsheetData;
diff --git a/tests/PhpSpreadsheetTests/Reader/XEEValidatorTest.php b/tests/PhpSpreadsheetTests/Reader/XEEValidatorTest.php
index a9a97314..372e51bb 100644
--- a/tests/PhpSpreadsheetTests/Reader/XEEValidatorTest.php
+++ b/tests/PhpSpreadsheetTests/Reader/XEEValidatorTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Reader;
 
 use PhpOffice\PhpSpreadsheet\Reader\BaseReader;
+use PHPUnit_Framework_TestCase;
 
-class XEEValidatorTest extends \PHPUnit_Framework_TestCase
+class XEEValidatorTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerInvalidXML
diff --git a/tests/PhpSpreadsheetTests/ReferenceHelperTest.php b/tests/PhpSpreadsheetTests/ReferenceHelperTest.php
index ecbcd081..1f7e0d56 100644
--- a/tests/PhpSpreadsheetTests/ReferenceHelperTest.php
+++ b/tests/PhpSpreadsheetTests/ReferenceHelperTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests;
 
 use PhpOffice\PhpSpreadsheet\ReferenceHelper;
+use PHPUnit_Framework_TestCase;
 
-class ReferenceHelperTest extends \PHPUnit_Framework_TestCase
+class ReferenceHelperTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/SampleTest.php b/tests/PhpSpreadsheetTests/SampleTest.php
index a7e1e075..ecbedfbd 100644
--- a/tests/PhpSpreadsheetTests/SampleTest.php
+++ b/tests/PhpSpreadsheetTests/SampleTest.php
@@ -2,7 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheetTests;
 
-class SampleTest extends \PHPUnit_Framework_TestCase
+use PhpOffice\PhpSpreadsheet\Helper\Sample;
+use PHPUnit_Framework_TestCase;
+
+class SampleTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @runInSeparateProcess
@@ -35,7 +38,7 @@ class SampleTest extends \PHPUnit_Framework_TestCase
             $skipped = array_merge($skipped, $tooLongToBeCovered);
         }
 
-        $helper = new \PhpOffice\PhpSpreadsheet\Helper\Sample();
+        $helper = new Sample();
         $samples = [];
         foreach ($helper->getSamples() as $name => $sample) {
             if (!in_array($name, $skipped)) {
diff --git a/tests/PhpSpreadsheetTests/SettingsTest.php b/tests/PhpSpreadsheetTests/SettingsTest.php
index 02a8c36b..ec0e12ea 100644
--- a/tests/PhpSpreadsheetTests/SettingsTest.php
+++ b/tests/PhpSpreadsheetTests/SettingsTest.php
@@ -2,7 +2,10 @@
 
 namespace PhpOffice\PhpSpreadsheetTests;
 
-class SettingsTest extends \PHPUnit_Framework_TestCase
+use PhpOffice\PhpSpreadsheet\Settings;
+use PHPUnit_Framework_TestCase;
+
+class SettingsTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @var string
@@ -22,15 +25,15 @@ class SettingsTest extends \PHPUnit_Framework_TestCase
 
     public function testGetXMLSettings()
     {
-        $result = \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions();
+        $result = Settings::getLibXmlLoaderOptions();
         $this->assertTrue((bool) ((LIBXML_DTDLOAD | LIBXML_DTDATTR) & $result));
         $this->assertFalse(libxml_disable_entity_loader());
     }
 
     public function testSetXMLSettings()
     {
-        \PhpOffice\PhpSpreadsheet\Settings::setLibXmlLoaderOptions(LIBXML_DTDLOAD | LIBXML_DTDATTR | LIBXML_DTDVALID);
-        $result = \PhpOffice\PhpSpreadsheet\Settings::getLibXmlLoaderOptions();
+        Settings::setLibXmlLoaderOptions(LIBXML_DTDLOAD | LIBXML_DTDATTR | LIBXML_DTDVALID);
+        $result = Settings::getLibXmlLoaderOptions();
         $this->assertTrue((bool) ((LIBXML_DTDLOAD | LIBXML_DTDATTR | LIBXML_DTDVALID) & $result));
         $this->assertFalse(libxml_disable_entity_loader());
     }
diff --git a/tests/PhpSpreadsheetTests/Shared/CodePageTest.php b/tests/PhpSpreadsheetTests/Shared/CodePageTest.php
index 337b8ed4..7841fe98 100644
--- a/tests/PhpSpreadsheetTests/Shared/CodePageTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/CodePageTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Exception;
 use PhpOffice\PhpSpreadsheet\Shared\CodePage;
+use PHPUnit_Framework_TestCase;
 
-class CodePageTest extends \PHPUnit_Framework_TestCase
+class CodePageTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerCodePage
diff --git a/tests/PhpSpreadsheetTests/Shared/DateTest.php b/tests/PhpSpreadsheetTests/Shared/DateTest.php
index 0439cf60..2e6d028d 100644
--- a/tests/PhpSpreadsheetTests/Shared/DateTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/DateTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\Date;
+use PHPUnit_Framework_TestCase;
 
-class DateTest extends \PHPUnit_Framework_TestCase
+class DateTest extends PHPUnit_Framework_TestCase
 {
     public function testSetExcelCalendar()
     {
diff --git a/tests/PhpSpreadsheetTests/Shared/FileTest.php b/tests/PhpSpreadsheetTests/Shared/FileTest.php
index eb802a0f..5f148a2a 100644
--- a/tests/PhpSpreadsheetTests/Shared/FileTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/FileTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\File;
+use PHPUnit_Framework_TestCase;
 
-class FileTest extends \PHPUnit_Framework_TestCase
+class FileTest extends PHPUnit_Framework_TestCase
 {
     public function testGetUseUploadTempDirectory()
     {
diff --git a/tests/PhpSpreadsheetTests/Shared/FontTest.php b/tests/PhpSpreadsheetTests/Shared/FontTest.php
index c104cb14..76a40d1c 100644
--- a/tests/PhpSpreadsheetTests/Shared/FontTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/FontTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\Font;
+use PHPUnit_Framework_TestCase;
 
-class FontTest extends \PHPUnit_Framework_TestCase
+class FontTest extends PHPUnit_Framework_TestCase
 {
     public function testGetAutoSizeMethod()
     {
diff --git a/tests/PhpSpreadsheetTests/Shared/PasswordHasherTest.php b/tests/PhpSpreadsheetTests/Shared/PasswordHasherTest.php
index 444883cb..271deefc 100644
--- a/tests/PhpSpreadsheetTests/Shared/PasswordHasherTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/PasswordHasherTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\PasswordHasher;
+use PHPUnit_Framework_TestCase;
 
-class PasswordHasherTest extends \PHPUnit_Framework_TestCase
+class PasswordHasherTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerHashPassword
diff --git a/tests/PhpSpreadsheetTests/Shared/StringTest.php b/tests/PhpSpreadsheetTests/Shared/StringTest.php
index 83643127..9fbaba33 100644
--- a/tests/PhpSpreadsheetTests/Shared/StringTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/StringTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
+use PHPUnit_Framework_TestCase;
 
-class StringTest extends \PHPUnit_Framework_TestCase
+class StringTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Shared/TimeZoneTest.php b/tests/PhpSpreadsheetTests/Shared/TimeZoneTest.php
index 58f791d1..706955c2 100644
--- a/tests/PhpSpreadsheetTests/Shared/TimeZoneTest.php
+++ b/tests/PhpSpreadsheetTests/Shared/TimeZoneTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Shared;
 
 use PhpOffice\PhpSpreadsheet\Shared\TimeZone;
+use PHPUnit_Framework_TestCase;
 
-class TimeZoneTest extends \PHPUnit_Framework_TestCase
+class TimeZoneTest extends PHPUnit_Framework_TestCase
 {
     public function testSetTimezone()
     {
diff --git a/tests/PhpSpreadsheetTests/Style/ColorTest.php b/tests/PhpSpreadsheetTests/Style/ColorTest.php
index 8dca92f1..6ed161d2 100644
--- a/tests/PhpSpreadsheetTests/Style/ColorTest.php
+++ b/tests/PhpSpreadsheetTests/Style/ColorTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Style;
 
 use PhpOffice\PhpSpreadsheet\Style\Color;
+use PHPUnit_Framework_TestCase;
 
-class ColorTest extends \PHPUnit_Framework_TestCase
+class ColorTest extends PHPUnit_Framework_TestCase
 {
     /**
      * @dataProvider providerColorGetRed
diff --git a/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php b/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php
index 01c51c59..af462e41 100644
--- a/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php
+++ b/tests/PhpSpreadsheetTests/Style/NumberFormatDateTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Style;
 
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PHPUnit_Framework_TestCase;
 
-class NumberFormatDateTest extends \PHPUnit_Framework_TestCase
+class NumberFormatDateTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php b/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
index d900962a..72c7fbe4 100644
--- a/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
+++ b/tests/PhpSpreadsheetTests/Style/NumberFormatTest.php
@@ -4,8 +4,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Style;
 
 use PhpOffice\PhpSpreadsheet\Shared\StringHelper;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
+use PHPUnit_Framework_TestCase;
 
-class NumberFormatTest extends \PHPUnit_Framework_TestCase
+class NumberFormatTest extends PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
diff --git a/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/Column/RuleTest.php b/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/Column/RuleTest.php
index 15d29f32..b7760e25 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/Column/RuleTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/Column/RuleTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Worksheet\AutoFilter\Column;
 
 use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PHPUnit_Framework_TestCase;
 
-class RuleTest extends \PHPUnit_Framework_TestCase
+class RuleTest extends PHPUnit_Framework_TestCase
 {
     private $testAutoFilterRuleObject;
     private $mockAutoFilterColumnObject;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/ColumnTest.php b/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/ColumnTest.php
index 8a92c8ad..e171e814 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/ColumnTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/AutoFilter/ColumnTest.php
@@ -3,8 +3,9 @@
 namespace PhpOffice\PhpSpreadsheetTests\Worksheet\AutoFilter;
 
 use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter;
+use PHPUnit_Framework_TestCase;
 
-class ColumnTest extends \PHPUnit_Framework_TestCase
+class ColumnTest extends PHPUnit_Framework_TestCase
 {
     private $testInitialColumn = 'H';
     private $testAutoFilterColumnObject;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/AutoFilterTest.php b/tests/PhpSpreadsheetTests/Worksheet/AutoFilterTest.php
index 7a943642..974dbd70 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/AutoFilterTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/AutoFilterTest.php
@@ -6,8 +6,9 @@ use PhpOffice\PhpSpreadsheet\Collection\Cells;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter;
 use PhpOffice\PhpSpreadsheet\Worksheet\AutoFilter\Column;
+use PHPUnit_Framework_TestCase;
 
-class AutoFilterTest extends \PHPUnit_Framework_TestCase
+class AutoFilterTest extends PHPUnit_Framework_TestCase
 {
     private $testInitialRange = 'H2:O256';
     private $testAutoFilterObject;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
index 997307a4..5af397a5 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/ColumnCellIteratorTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\ColumnCellIterator;
+use PHPUnit_Framework_TestCase;
 
-class ColumnCellIteratorTest extends \PHPUnit_Framework_TestCase
+class ColumnCellIteratorTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockColumnCell;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/ColumnIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/ColumnIteratorTest.php
index 3fdcd446..3f107f45 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/ColumnIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/ColumnIteratorTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Column;
 use PhpOffice\PhpSpreadsheet\Worksheet\ColumnIterator;
+use PHPUnit_Framework_TestCase;
 
-class ColumnIteratorTest extends \PHPUnit_Framework_TestCase
+class ColumnIteratorTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockColumn;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
index e63d3f95..edb76a55 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowCellIteratorTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Cell;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\RowCellIterator;
+use PHPUnit_Framework_TestCase;
 
-class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
+class RowCellIteratorTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockRowCell;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/RowIteratorTest.php b/tests/PhpSpreadsheetTests/Worksheet/RowIteratorTest.php
index 1bfa69d7..071baf7d 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/RowIteratorTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/RowIteratorTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Row;
 use PhpOffice\PhpSpreadsheet\Worksheet\RowIterator;
+use PHPUnit_Framework_TestCase;
 
-class RowIteratorTest extends \PHPUnit_Framework_TestCase
+class RowIteratorTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockRow;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php b/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php
index 7c1c3487..c8730e25 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/WorksheetColumnTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Column;
 use PhpOffice\PhpSpreadsheet\Worksheet\ColumnCellIterator;
+use PHPUnit_Framework_TestCase;
 
-class WorksheetColumnTest extends \PHPUnit_Framework_TestCase
+class WorksheetColumnTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockColumn;
diff --git a/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php b/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php
index 59901f44..d16149fb 100644
--- a/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php
+++ b/tests/PhpSpreadsheetTests/Worksheet/WorksheetRowTest.php
@@ -5,8 +5,9 @@ namespace PhpOffice\PhpSpreadsheetTests\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet;
 use PhpOffice\PhpSpreadsheet\Worksheet\Row;
 use PhpOffice\PhpSpreadsheet\Worksheet\RowCellIterator;
+use PHPUnit_Framework_TestCase;
 
-class WorksheetRowTest extends \PHPUnit_Framework_TestCase
+class WorksheetRowTest extends PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
     public $mockRow;
diff --git a/tests/PhpSpreadsheetTests/Writer/Ods/ContentTest.php b/tests/PhpSpreadsheetTests/Writer/Ods/ContentTest.php
index 8a4aae64..00cf5cc5 100644
--- a/tests/PhpSpreadsheetTests/Writer/Ods/ContentTest.php
+++ b/tests/PhpSpreadsheetTests/Writer/Ods/ContentTest.php
@@ -12,8 +12,9 @@ use PhpOffice\PhpSpreadsheet\Style\Font;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use PhpOffice\PhpSpreadsheet\Writer\Ods;
 use PhpOffice\PhpSpreadsheet\Writer\Ods\Content;
+use PHPUnit_Framework_TestCase;
 
-class ContentTest extends \PHPUnit_Framework_TestCase
+class ContentTest extends PHPUnit_Framework_TestCase
 {
     private $samplesPath = __DIR__ . '/../../../data/Writer/Ods';