diff --git a/tests/PhpSpreadsheet/Calculation/DateTimeTest.php b/tests/PhpSpreadsheet/Calculation/DateTimeTest.php
index 9300c604..6e7c01ae 100644
--- a/tests/PhpSpreadsheet/Calculation/DateTimeTest.php
+++ b/tests/PhpSpreadsheet/Calculation/DateTimeTest.php
@@ -26,7 +26,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DATE'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DATE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -79,7 +79,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DATEVALUE'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DATEVALUE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -116,7 +116,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'YEAR'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'YEAR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -132,7 +132,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'MONTHOFYEAR'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'MONTHOFYEAR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -149,7 +149,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'WEEKOFYEAR'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'WEEKOFYEAR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -166,7 +166,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DAYOFWEEK'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DAYOFWEEK'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -182,7 +182,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DAYOFMONTH'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DAYOFMONTH'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -198,7 +198,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'TIME'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'TIME'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -235,7 +235,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'TIMEVALUE'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'TIMEVALUE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -272,7 +272,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'HOUROFDAY'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'HOUROFDAY'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -288,7 +288,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'MINUTEOFHOUR'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'MINUTEOFHOUR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -304,7 +304,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'SECONDOFMINUTE'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'SECONDOFMINUTE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -320,7 +320,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'NETWORKDAYS'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'NETWORKDAYS'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -336,7 +336,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'WORKDAY'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'WORKDAY'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -352,7 +352,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'EDATE'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'EDATE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -389,7 +389,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'EOMONTH'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'EOMONTH'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -427,7 +427,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DATEDIF'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DATEDIF'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -443,7 +443,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'DAYS360'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'DAYS360'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -460,7 +460,7 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\DateTime', 'YEARFRAC'), $args);
+        $result = call_user_func_array(array(DateTime::class, 'YEARFRAC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/EngineeringTest.php b/tests/PhpSpreadsheet/Calculation/EngineeringTest.php
index 5a58ed20..ba74e451 100644
--- a/tests/PhpSpreadsheet/Calculation/EngineeringTest.php
+++ b/tests/PhpSpreadsheet/Calculation/EngineeringTest.php
@@ -2,6 +2,9 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation\Engineering;
+use PHPExcel\Calculation\Functions;
+
 class EngineeringTest extends \PHPUnit_Framework_TestCase
 {
 
@@ -13,7 +16,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     public function setUp()
     {
         $this->complexAssert = new \PhpSpreadsheet\Tests\Custom\ComplexAssert();
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     public function tearDown()
@@ -28,7 +31,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BESSELI'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BESSELI'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -44,7 +47,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BESSELJ'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BESSELJ'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -60,7 +63,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BESSELK'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BESSELK'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -76,7 +79,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BESSELY'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BESSELY'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -92,7 +95,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','COMPLEX'), $args);
+        $result = call_user_func_array(array(Engineering::class,'COMPLEX'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -108,7 +111,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMAGINARY'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMAGINARY'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -124,7 +127,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMREAL'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMREAL'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -140,7 +143,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMABS'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMABS'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -157,7 +160,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMARGUMENT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMARGUMENT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -173,7 +176,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMCONJUGATE'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMCONJUGATE'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -189,7 +192,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMCOS'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMCOS'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -206,7 +209,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMDIV'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMDIV'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -222,7 +225,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMEXP'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMEXP'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -238,7 +241,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMLN'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMLN'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -254,7 +257,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMLOG2'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMLOG2'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -270,7 +273,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMLOG10'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMLOG10'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -287,7 +290,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMPOWER'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMPOWER'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -303,7 +306,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMPRODUCT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMPRODUCT'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -319,7 +322,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMSIN'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMSIN'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -335,7 +338,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMSQRT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMSQRT'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -352,7 +355,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMSUB'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMSUB'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -369,7 +372,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','IMSUM'), $args);
+        $result = call_user_func_array(array(Engineering::class,'IMSUM'), $args);
         $this->assertTrue($this->complexAssert->assertComplexEquals($expectedResult, $result, 1E-8), $this->complexAssert->getErrorMessage());
     }
 
@@ -385,7 +388,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','ERF'), $args);
+        $result = call_user_func_array(array(Engineering::class,'ERF'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -401,7 +404,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','ERFC'), $args);
+        $result = call_user_func_array(array(Engineering::class,'ERFC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -417,7 +420,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BINTODEC'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BINTODEC'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -433,7 +436,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BINTOHEX'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BINTOHEX'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -449,7 +452,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','BINTOOCT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'BINTOOCT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -465,7 +468,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','DECTOBIN'), $args);
+        $result = call_user_func_array(array(Engineering::class,'DECTOBIN'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -481,7 +484,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','DECTOHEX'), $args);
+        $result = call_user_func_array(array(Engineering::class,'DECTOHEX'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -497,7 +500,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','DECTOOCT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'DECTOOCT'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -513,7 +516,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','HEXTOBIN'), $args);
+        $result = call_user_func_array(array(Engineering::class,'HEXTOBIN'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -529,7 +532,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','HEXTODEC'), $args);
+        $result = call_user_func_array(array(Engineering::class,'HEXTODEC'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -545,7 +548,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','HEXTOOCT'), $args);
+        $result = call_user_func_array(array(Engineering::class,'HEXTOOCT'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -561,7 +564,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','OCTTOBIN'), $args);
+        $result = call_user_func_array(array(Engineering::class,'OCTTOBIN'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -577,7 +580,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','OCTTODEC'), $args);
+        $result = call_user_func_array(array(Engineering::class,'OCTTODEC'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -593,7 +596,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','OCTTOHEX'), $args);
+        $result = call_user_func_array(array(Engineering::class,'OCTTOHEX'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -609,7 +612,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','DELTA'), $args);
+        $result = call_user_func_array(array(Engineering::class,'DELTA'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -625,7 +628,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','GESTEP'), $args);
+        $result = call_user_func_array(array(Engineering::class,'GESTEP'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
@@ -636,25 +639,25 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
 
     public function testGetConversionGroups()
     {
-        $result = \PHPExcel\Calculation\Engineering::getConversionGroups();
+        $result = Engineering::getConversionGroups();
         $this->assertInternalType('array', $result);
     }
 
     public function testGetConversionGroupUnits()
     {
-        $result = \PHPExcel\Calculation\Engineering::getConversionGroupUnits();
+        $result = Engineering::getConversionGroupUnits();
         $this->assertInternalType('array', $result);
     }
 
     public function testGetConversionGroupUnitDetails()
     {
-        $result = \PHPExcel\Calculation\Engineering::getConversionGroupUnitDetails();
+        $result = Engineering::getConversionGroupUnitDetails();
         $this->assertInternalType('array', $result);
     }
 
     public function testGetConversionMultipliers()
     {
-        $result = \PHPExcel\Calculation\Engineering::getConversionMultipliers();
+        $result = Engineering::getConversionMultipliers();
         $this->assertInternalType('array', $result);
     }
 
@@ -665,7 +668,7 @@ class EngineeringTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Engineering','CONVERTUOM'), $args);
+        $result = call_user_func_array(array(Engineering::class,'CONVERTUOM'), $args);
         $this->assertEquals($expectedResult, $result, null);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/FinancialTest.php b/tests/PhpSpreadsheet/Calculation/FinancialTest.php
index 76dfb6d3..e9f900fb 100644
--- a/tests/PhpSpreadsheet/Calculation/FinancialTest.php
+++ b/tests/PhpSpreadsheet/Calculation/FinancialTest.php
@@ -2,12 +2,15 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation\Financial;
+use PHPExcel\Calculation\Functions;
+
 class FinancialTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     /**
@@ -18,7 +21,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','ACCRINT'), $args);
+        $result = call_user_func_array(array(Financial::class,'ACCRINT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -34,7 +37,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','ACCRINTM'), $args);
+        $result = call_user_func_array(array(Financial::class,'ACCRINTM'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -50,7 +53,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','AMORDEGRC'), $args);
+        $result = call_user_func_array(array(Financial::class,'AMORDEGRC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -66,7 +69,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','AMORLINC'), $args);
+        $result = call_user_func_array(array(Financial::class,'AMORLINC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -82,7 +85,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPDAYBS'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPDAYBS'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -98,7 +101,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPDAYS'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPDAYS'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -114,7 +117,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPDAYSNC'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPDAYSNC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -130,7 +133,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPNCD'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPNCD'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -146,7 +149,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPNUM'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPNUM'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -162,7 +165,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','COUPPCD'), $args);
+        $result = call_user_func_array(array(Financial::class,'COUPPCD'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -178,7 +181,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','CUMIPMT'), $args);
+        $result = call_user_func_array(array(Financial::class,'CUMIPMT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -194,7 +197,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','CUMPRINC'), $args);
+        $result = call_user_func_array(array(Financial::class,'CUMPRINC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -210,7 +213,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','DB'), $args);
+        $result = call_user_func_array(array(Financial::class,'DB'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -226,7 +229,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','DDB'), $args);
+        $result = call_user_func_array(array(Financial::class,'DDB'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -242,7 +245,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','DISC'), $args);
+        $result = call_user_func_array(array(Financial::class,'DISC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -258,7 +261,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','DOLLARDE'), $args);
+        $result = call_user_func_array(array(Financial::class,'DOLLARDE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -274,7 +277,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','DOLLARFR'), $args);
+        $result = call_user_func_array(array(Financial::class,'DOLLARFR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -290,7 +293,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','EFFECT'), $args);
+        $result = call_user_func_array(array(Financial::class,'EFFECT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -306,7 +309,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','FV'), $args);
+        $result = call_user_func_array(array(Financial::class,'FV'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -322,7 +325,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','FVSCHEDULE'), $args);
+        $result = call_user_func_array(array(Financial::class,'FVSCHEDULE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -338,7 +341,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','INTRATE'), $args);
+        $result = call_user_func_array(array(Financial::class,'INTRATE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -354,7 +357,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','IPMT'), $args);
+        $result = call_user_func_array(array(Financial::class,'IPMT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -370,7 +373,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','IRR'), $args);
+        $result = call_user_func_array(array(Financial::class,'IRR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -386,7 +389,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','ISPMT'), $args);
+        $result = call_user_func_array(array(Financial::class,'ISPMT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -402,7 +405,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','MIRR'), $args);
+        $result = call_user_func_array(array(Financial::class,'MIRR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -418,7 +421,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','NOMINAL'), $args);
+        $result = call_user_func_array(array(Financial::class,'NOMINAL'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -434,7 +437,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','NPER'), $args);
+        $result = call_user_func_array(array(Financial::class,'NPER'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -450,7 +453,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','NPV'), $args);
+        $result = call_user_func_array(array(Financial::class,'NPV'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -467,7 +470,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','PRICE'), $args);
+        $result = call_user_func_array(array(Financial::class,'PRICE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -484,7 +487,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','RATE'), $args);
+        $result = call_user_func_array(array(Financial::class,'RATE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -501,7 +504,7 @@ class FinancialTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Financial','XIRR'), $args);
+        $result = call_user_func_array(array(Financial::class,'XIRR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/FunctionsTest.php b/tests/PhpSpreadsheet/Calculation/FunctionsTest.php
index af391dd9..801f76a0 100644
--- a/tests/PhpSpreadsheet/Calculation/FunctionsTest.php
+++ b/tests/PhpSpreadsheet/Calculation/FunctionsTest.php
@@ -2,59 +2,61 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation\Functions;
+
 class FunctionsTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     public function testDUMMY()
     {
-        $result = \PHPExcel\Calculation\Functions::DUMMY();
+        $result = Functions::DUMMY();
         $this->assertEquals('#Not Yet Implemented', $result);
     }
 
     public function testDIV0()
     {
-        $result = \PHPExcel\Calculation\Functions::DIV0();
+        $result = Functions::DIV0();
         $this->assertEquals('#DIV/0!', $result);
     }
 
     public function testNA()
     {
-        $result = \PHPExcel\Calculation\Functions::NA();
+        $result = Functions::NA();
         $this->assertEquals('#N/A', $result);
     }
 
     public function testNAN()
     {
-        $result = \PHPExcel\Calculation\Functions::NAN();
+        $result = Functions::NAN();
         $this->assertEquals('#NUM!', $result);
     }
 
     public function testNAME()
     {
-        $result = \PHPExcel\Calculation\Functions::NAME();
+        $result = Functions::NAME();
         $this->assertEquals('#NAME?', $result);
     }
 
     public function testREF()
     {
-        $result = \PHPExcel\Calculation\Functions::REF();
+        $result = Functions::REF();
         $this->assertEquals('#REF!', $result);
     }
 
     public function testNULL()
     {
-        $result = \PHPExcel\Calculation\Functions::null();
+        $result = Functions::null();
         $this->assertEquals('#NULL!', $result);
     }
 
     public function testVALUE()
     {
-        $result = \PHPExcel\Calculation\Functions::VALUE();
+        $result = Functions::VALUE();
         $this->assertEquals('#VALUE!', $result);
     }
 
@@ -65,7 +67,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isBlank'), $args);
+        $result = call_user_func_array(array(Functions::class,'isBlank'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -81,7 +83,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isErr'), $args);
+        $result = call_user_func_array(array(Functions::class,'isErr'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -97,7 +99,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isError'), $args);
+        $result = call_user_func_array(array(Functions::class,'isError'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -113,7 +115,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','errorType'), $args);
+        $result = call_user_func_array(array(Functions::class,'errorType'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -129,7 +131,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isLogical'), $args);
+        $result = call_user_func_array(array(Functions::class,'isLogical'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -145,7 +147,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isNa'), $args);
+        $result = call_user_func_array(array(Functions::class,'isNa'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -161,7 +163,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isNumber'), $args);
+        $result = call_user_func_array(array(Functions::class,'isNumber'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -177,7 +179,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isText'), $args);
+        $result = call_user_func_array(array(Functions::class,'isText'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -193,7 +195,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isNonText'), $args);
+        $result = call_user_func_array(array(Functions::class,'isNonText'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -209,7 +211,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isEven'), $args);
+        $result = call_user_func_array(array(Functions::class,'isEven'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -225,7 +227,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','isOdd'), $args);
+        $result = call_user_func_array(array(Functions::class,'isOdd'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -241,7 +243,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','TYPE'), $args);
+        $result = call_user_func_array(array(Functions::class,'TYPE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
@@ -257,7 +259,7 @@ class FunctionsTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Functions','n'), $args);
+        $result = call_user_func_array(array(Functions::class,'n'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/LogicalTest.php b/tests/PhpSpreadsheet/Calculation/LogicalTest.php
index 8d01df06..9a0f7854 100644
--- a/tests/PhpSpreadsheet/Calculation/LogicalTest.php
+++ b/tests/PhpSpreadsheet/Calculation/LogicalTest.php
@@ -2,23 +2,26 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation\Functions;
+use PHPExcel\Calculation\Logical;
+
 class LogicalTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     public function testTRUE()
     {
-        $result = \PHPExcel\Calculation\Logical::TRUE();
+        $result = Logical::TRUE();
         $this->assertEquals(true, $result);
     }
 
     public function testFALSE()
     {
-        $result = \PHPExcel\Calculation\Logical::FALSE();
+        $result = Logical::FALSE();
         $this->assertEquals(false, $result);
     }
 
@@ -29,7 +32,7 @@ class LogicalTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Logical','logicalAnd'), $args);
+        $result = call_user_func_array(array(Logical::class,'logicalAnd'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -45,7 +48,7 @@ class LogicalTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Logical','logicalOr'), $args);
+        $result = call_user_func_array(array(Logical::class,'logicalOr'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -61,7 +64,7 @@ class LogicalTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Logical','NOT'), $args);
+        $result = call_user_func_array(array(Logical::class,'NOT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -77,7 +80,7 @@ class LogicalTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Logical','statementIf'), $args);
+        $result = call_user_func_array(array(Logical::class,'statementIf'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -93,7 +96,7 @@ class LogicalTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\Logical','IFERROR'), $args);
+        $result = call_user_func_array(array(Logical::class,'IFERROR'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/LookupRefTest.php b/tests/PhpSpreadsheet/Calculation/LookupRefTest.php
index d1134c63..077f2ca2 100644
--- a/tests/PhpSpreadsheet/Calculation/LookupRefTest.php
+++ b/tests/PhpSpreadsheet/Calculation/LookupRefTest.php
@@ -2,6 +2,9 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation\Functions;
+use PHPExcel\Calculation\LookupRef;
+
 /**
  * Class LookupRefTest
  * @package PHPExcel\Calculation
@@ -11,7 +14,7 @@ class LookupRefTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     /**
@@ -22,7 +25,7 @@ class LookupRefTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\LookupRef','HLOOKUP'), $args);
+        $result = call_user_func_array(array(LookupRef::class,'HLOOKUP'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -39,7 +42,7 @@ class LookupRefTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\LookupRef','VLOOKUP'), $args);
+        $result = call_user_func_array(array(LookupRef::class,'VLOOKUP'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/MathTrigTest.php b/tests/PhpSpreadsheet/Calculation/MathTrigTest.php
index 9715e39c..75b00473 100644
--- a/tests/PhpSpreadsheet/Calculation/MathTrigTest.php
+++ b/tests/PhpSpreadsheet/Calculation/MathTrigTest.php
@@ -2,12 +2,16 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Calculation;
+use PHPExcel\Calculation\Functions;
+use PHPExcel\Calculation\MathTrig;
+
 class MathTrigTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     /**
@@ -17,7 +21,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','ATAN2'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'ATAN2'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -33,7 +37,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','CEILING'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'CEILING'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -49,7 +53,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','COMBIN'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'COMBIN'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -65,7 +69,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','EVEN'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'EVEN'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -81,7 +85,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','ODD'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'ODD'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -97,7 +101,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','FACT'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'FACT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -113,7 +117,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','FACTDOUBLE'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'FACTDOUBLE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -129,7 +133,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','FLOOR'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'FLOOR'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -145,7 +149,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','GCD'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'GCD'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -161,7 +165,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','LCM'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'LCM'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -177,7 +181,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','INT'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'INT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -193,7 +197,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','SIGN'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'SIGN'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -209,7 +213,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','POWER'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'POWER'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -225,7 +229,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','logBase'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'logBase'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -241,7 +245,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MOD'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'MOD'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -258,7 +262,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MDETERM'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'MDETERM'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -275,7 +279,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MINVERSE'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'MINVERSE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -292,7 +296,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MMULT'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'MMULT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -308,7 +312,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MULTINOMIAL'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'MULTINOMIAL'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -324,9 +328,9 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        \PHPExcel\Calculation::setArrayReturnType(\PHPExcel\Calculation::RETURN_ARRAY_AS_VALUE);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','MROUND'), $args);
-        \PHPExcel\Calculation::setArrayReturnType(\PHPExcel\Calculation::RETURN_ARRAY_AS_ARRAY);
+        Calculation::setArrayReturnType(Calculation::RETURN_ARRAY_AS_VALUE);
+        $result = call_user_func_array(array(MathTrig::class,'MROUND'), $args);
+        Calculation::setArrayReturnType(Calculation::RETURN_ARRAY_AS_ARRAY);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -342,7 +346,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','PRODUCT'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'PRODUCT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -358,7 +362,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','QUOTIENT'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'QUOTIENT'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -374,7 +378,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','ROUNDUP'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'ROUNDUP'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -390,7 +394,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','ROUNDDOWN'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'ROUNDDOWN'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -406,7 +410,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','SERIESSUM'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'SERIESSUM'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -422,7 +426,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','SUMSQ'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'SUMSQ'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -438,7 +442,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','TRUNC'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'TRUNC'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -454,7 +458,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','ROMAN'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'ROMAN'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -470,7 +474,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig','SQRTPI'), $args);
+        $result = call_user_func_array(array(MathTrig::class,'SQRTPI'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
@@ -486,7 +490,7 @@ class MathTrigTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\MathTrig', 'SUMIF'), $args);
+        $result = call_user_func_array(array(MathTrig::class, 'SUMIF'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-12);
     }
 
diff --git a/tests/PhpSpreadsheet/Calculation/TextDataTest.php b/tests/PhpSpreadsheet/Calculation/TextDataTest.php
index 949ce7ea..f438865d 100644
--- a/tests/PhpSpreadsheet/Calculation/TextDataTest.php
+++ b/tests/PhpSpreadsheet/Calculation/TextDataTest.php
@@ -2,12 +2,16 @@
 
 namespace PhpSpreadsheet\Tests\Calculation;
 
+use PHPExcel\Shared\StringHelper;
+use PHPExcel\Calculation\Functions;
+use PHPExcel\Calculation\TextData;
+
 class TextDataTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Calculation\Functions::setCompatibilityMode(\PHPExcel\Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     /**
@@ -17,7 +21,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','CHARACTER'), $args);
+        $result = call_user_func_array(array(TextData::class,'CHARACTER'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -33,7 +37,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','ASCIICODE'), $args);
+        $result = call_user_func_array(array(TextData::class,'ASCIICODE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -49,7 +53,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','CONCATENATE'), $args);
+        $result = call_user_func_array(array(TextData::class,'CONCATENATE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -65,7 +69,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','LEFT'), $args);
+        $result = call_user_func_array(array(TextData::class,'LEFT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -81,7 +85,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','MID'), $args);
+        $result = call_user_func_array(array(TextData::class,'MID'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -97,7 +101,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','RIGHT'), $args);
+        $result = call_user_func_array(array(TextData::class,'RIGHT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -113,7 +117,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','LOWERCASE'), $args);
+        $result = call_user_func_array(array(TextData::class,'LOWERCASE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -129,7 +133,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','UPPERCASE'), $args);
+        $result = call_user_func_array(array(TextData::class,'UPPERCASE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -145,7 +149,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','PROPERCASE'), $args);
+        $result = call_user_func_array(array(TextData::class,'PROPERCASE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -161,7 +165,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','STRINGLENGTH'), $args);
+        $result = call_user_func_array(array(TextData::class,'STRINGLENGTH'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -177,7 +181,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','SEARCHINSENSITIVE'), $args);
+        $result = call_user_func_array(array(TextData::class,'SEARCHINSENSITIVE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -193,7 +197,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','SEARCHSENSITIVE'), $args);
+        $result = call_user_func_array(array(TextData::class,'SEARCHSENSITIVE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -209,7 +213,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','REPLACE'), $args);
+        $result = call_user_func_array(array(TextData::class,'REPLACE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -225,7 +229,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','SUBSTITUTE'), $args);
+        $result = call_user_func_array(array(TextData::class,'SUBSTITUTE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -241,7 +245,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','TRIMSPACES'), $args);
+        $result = call_user_func_array(array(TextData::class,'TRIMSPACES'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -257,7 +261,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','TRIMNONPRINTABLE'), $args);
+        $result = call_user_func_array(array(TextData::class,'TRIMNONPRINTABLE'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -273,7 +277,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','DOLLAR'), $args);
+        $result = call_user_func_array(array(TextData::class,'DOLLAR'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -289,7 +293,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','FIXEDFORMAT'), $args);
+        $result = call_user_func_array(array(TextData::class,'FIXEDFORMAT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -305,7 +309,7 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData','RETURNSTRING'), $args);
+        $result = call_user_func_array(array(TextData::class,'RETURNSTRING'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -320,13 +324,13 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
     public function testTEXT()
     {
         //    Enforce decimal and thousands separator values to UK/US, and currency code to USD
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setDecimalSeparator'), '.');
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setThousandsSeparator'), ',');
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setCurrencyCode'), '$');
+        call_user_func(array(StringHelper::class, 'setDecimalSeparator'), '.');
+        call_user_func(array(StringHelper::class, 'setThousandsSeparator'), ',');
+        call_user_func(array(StringHelper::class, 'setCurrencyCode'), '$');
 
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData', 'TEXTFORMAT'), $args);
+        $result = call_user_func_array(array(TextData::class, 'TEXTFORMAT'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -340,13 +344,13 @@ class TextDataTest extends \PHPUnit_Framework_TestCase
      */
     public function testVALUE()
     {
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setDecimalSeparator'), '.');
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setThousandsSeparator'), ' ');
-        call_user_func(array('\PHPExcel\Shared\StringHelper', 'setCurrencyCode'), '$');
+        call_user_func(array(StringHelper::class, 'setDecimalSeparator'), '.');
+        call_user_func(array(StringHelper::class, 'setThousandsSeparator'), ' ');
+        call_user_func(array(StringHelper::class, 'setCurrencyCode'), '$');
 
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Calculation\TextData', 'VALUE'), $args);
+        $result = call_user_func_array(array(TextData::class, 'VALUE'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-8);
     }
 
diff --git a/tests/PhpSpreadsheet/CalculationTest.php b/tests/PhpSpreadsheet/CalculationTest.php
index 5d72100b..4c33fee4 100644
--- a/tests/PhpSpreadsheet/CalculationTest.php
+++ b/tests/PhpSpreadsheet/CalculationTest.php
@@ -1,12 +1,15 @@
 <?php
 
-namespace PHPExcel;
+namespace PhpSpreadsheet\Tests;
+
+use PHPExcel\Calculation;
+use PHPExcel\Calculation\Functions;
 
 class CalculationTest extends \PHPUnit_Framework_TestCase
 {
     public function setUp()
     {
-        Calculation\Functions::setCompatibilityMode(Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
     }
 
     /**
@@ -14,11 +17,11 @@ class CalculationTest extends \PHPUnit_Framework_TestCase
      */
     public function testBinaryComparisonOperation($formula, $expectedResultExcel, $expectedResultOpenOffice)
     {
-        Calculation\Functions::setCompatibilityMode(Calculation\Functions::COMPATIBILITY_EXCEL);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_EXCEL);
         $resultExcel = Calculation::getInstance()->_calculateFormulaValue($formula);
         $this->assertEquals($expectedResultExcel, $resultExcel, 'should be Excel compatible');
 
-        Calculation\Functions::setCompatibilityMode(Calculation\Functions::COMPATIBILITY_OPENOFFICE);
+        Functions::setCompatibilityMode(Functions::COMPATIBILITY_OPENOFFICE);
         $resultOpenOffice = Calculation::getInstance()->_calculateFormulaValue($formula);
         $this->assertEquals($expectedResultOpenOffice, $resultOpenOffice, 'should be OpenOffice compatible');
     }
diff --git a/tests/PhpSpreadsheet/Cell/AdvancedValueBinderTest.php b/tests/PhpSpreadsheet/Cell/AdvancedValueBinderTest.php
index 684a7eda..3cfa3aa7 100644
--- a/tests/PhpSpreadsheet/Cell/AdvancedValueBinderTest.php
+++ b/tests/PhpSpreadsheet/Cell/AdvancedValueBinderTest.php
@@ -2,6 +2,14 @@
 
 namespace PhpSpreadsheet\Tests\Cell;
 
+use PHPExcel\Worksheet;
+use PHPExcel\Style\NumberFormat;
+use PHPExcel\Shared\StringHelper;
+use PHPExcel\Cell;
+use PHPExcel\Cell\AdvancedValueBinder;
+use PHPExcel\Cell\DataType;
+use PHPExcel\CachedObjectStorage\Memory;
+
 class AdvancedValueBinderTest extends \PHPUnit_Framework_TestCase
 {
     public function setUp()
@@ -14,14 +22,14 @@ class AdvancedValueBinderTest extends \PHPUnit_Framework_TestCase
 
     public function provider()
     {
-        if (!class_exists('\\PHPExcel\\Style\\NumberFormat')) {
+        if (!class_exists(NumberFormat::class)) {
             $this->setUp();
         }
-        $currencyUSD = \PHPExcel\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE;
-        $currencyEURO = str_replace('$', '€', \PHPExcel\Style\NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
+        $currencyUSD = NumberFormat::FORMAT_CURRENCY_USD_SIMPLE;
+        $currencyEURO = str_replace('$', '€', NumberFormat::FORMAT_CURRENCY_USD_SIMPLE);
 
         return array(
-            array('10%', 0.1, \PHPExcel\Style\NumberFormat::FORMAT_PERCENTAGE_00, ',', '.', '$'),
+            array('10%', 0.1, NumberFormat::FORMAT_PERCENTAGE_00, ',', '.', '$'),
             array('$10.11', 10.11, $currencyUSD, ',', '.', '$'),
             array('$1,010.12', 1010.12, $currencyUSD, ',', '.', '$'),
             array('$20,20', 20.2, $currencyUSD, '.', ',', '$'),
@@ -38,10 +46,10 @@ class AdvancedValueBinderTest extends \PHPUnit_Framework_TestCase
     public function testCurrency($value, $valueBinded, $format, $thousandsSeparator, $decimalSeparator, $currencyCode)
     {
         $sheet = $this->getMock(
-            '\\PHPExcel\\Worksheet',
+            Worksheet::class,
             array('getStyle', 'getNumberFormat', 'setFormatCode','getCellCacheController')
         );
-        $cache = $this->getMockBuilder('\\PHPExcel\\CachedObjectStorage\\Memory')
+        $cache = $this->getMockBuilder(Memory::class)
             ->disableOriginalConstructor()
             ->getMock();
         $cache->expects($this->any())
@@ -62,13 +70,13 @@ class AdvancedValueBinderTest extends \PHPUnit_Framework_TestCase
                  ->method('getCellCacheController')
                  ->will($this->returnValue($cache));
 
-        \PHPExcel\Shared\StringHelper::setCurrencyCode($currencyCode);
-        \PHPExcel\Shared\StringHelper::setDecimalSeparator($decimalSeparator);
-        \PHPExcel\Shared\StringHelper::setThousandsSeparator($thousandsSeparator);
+        StringHelper::setCurrencyCode($currencyCode);
+        StringHelper::setDecimalSeparator($decimalSeparator);
+        StringHelper::setThousandsSeparator($thousandsSeparator);
 
-        $cell = new \PHPExcel\Cell(null, \PHPExcel\Cell\DataType::TYPE_STRING, $sheet);
+        $cell = new Cell(null, DataType::TYPE_STRING, $sheet);
 
-        $binder = new \PHPExcel\Cell\AdvancedValueBinder();
+        $binder = new AdvancedValueBinder();
         $binder->bindValue($cell, $value);
         $this->assertEquals($valueBinded, $cell->getValue());
     }
diff --git a/tests/PhpSpreadsheet/Cell/DataTypeTest.php b/tests/PhpSpreadsheet/Cell/DataTypeTest.php
index f8ae5bf8..88f8f785 100644
--- a/tests/PhpSpreadsheet/Cell/DataTypeTest.php
+++ b/tests/PhpSpreadsheet/Cell/DataTypeTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Cell;
 
+use PHPExcel\Cell\DataType;
+
 class DataTypeTest extends \PHPUnit_Framework_TestCase
 {
 
@@ -15,7 +17,7 @@ class DataTypeTest extends \PHPUnit_Framework_TestCase
 
     public function testGetErrorCodes()
     {
-        $result = call_user_func(array('\\PHPExcel\\Cell\\DataType','getErrorCodes'));
+        $result = call_user_func(array(DataType::class,'getErrorCodes'));
         $this->assertInternalType('array', $result);
         $this->assertGreaterThan(0, count($result));
         $this->assertArrayHasKey('#NULL!', $result);
diff --git a/tests/PhpSpreadsheet/Cell/DefaultValueBinderTest.php b/tests/PhpSpreadsheet/Cell/DefaultValueBinderTest.php
index 10e8e1f8..88003c79 100644
--- a/tests/PhpSpreadsheet/Cell/DefaultValueBinderTest.php
+++ b/tests/PhpSpreadsheet/Cell/DefaultValueBinderTest.php
@@ -2,6 +2,11 @@
 
 namespace PhpSpreadsheet\Tests\Cell;
 
+use PHPExcel\Cell\DefaultValueBinder;
+use PHPExcel\Cell;
+use PHPExcel\RichText;
+use PHPExcel\Cell\DataType;
+
 class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
 {
     protected $cellStub;
@@ -17,7 +22,7 @@ class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
     protected function createCellStub()
     {
         // Create a stub for the Cell class.
-        $this->cellStub = $this->getMockBuilder('\\PHPExcel\\Cell')
+        $this->cellStub = $this->getMockBuilder(Cell::class)
             ->disableOriginalConstructor()
             ->getMock();
         // Configure the stub.
@@ -32,7 +37,7 @@ class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
     public function testBindValue($value)
     {
         $this->createCellStub();
-        $binder = new \PHPExcel\Cell\DefaultValueBinder();
+        $binder = new DefaultValueBinder();
         $result = $binder->bindValue($this->cellStub, $value);
         $this->assertTrue($result);
     }
@@ -61,7 +66,7 @@ class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
     public function testDataTypeForValue()
     {
         list($args, $expectedResult) = func_get_args();
-        $result = call_user_func_array(array('\\PHPExcel\\Cell\\DefaultValueBinder','dataTypeForValue'), $args);
+        $result = call_user_func_array(array(DefaultValueBinder::class,'dataTypeForValue'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -72,11 +77,11 @@ class DefaultValueBinderTest extends \PHPUnit_Framework_TestCase
 
     public function testDataTypeForRichTextObject()
     {
-        $objRichText = new \PHPExcel\RichText();
+        $objRichText = new RichText();
         $objRichText->createText('Hello World');
 
-        $expectedResult = \PHPExcel\Cell\DataType::TYPE_INLINE;
-        $result = call_user_func(array('\\PHPExcel\\Cell\\DefaultValueBinder','dataTypeForValue'), $objRichText);
+        $expectedResult = DataType::TYPE_INLINE;
+        $result = call_user_func(array(DefaultValueBinder::class,'dataTypeForValue'), $objRichText);
         $this->assertEquals($expectedResult, $result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Cell/HyperlinkTest.php b/tests/PhpSpreadsheet/Cell/HyperlinkTest.php
index 701b86ad..8acdcfae 100644
--- a/tests/PhpSpreadsheet/Cell/HyperlinkTest.php
+++ b/tests/PhpSpreadsheet/Cell/HyperlinkTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Cell;
 
+use PHPExcel\Cell\Hyperlink;
+
 class HyperlinkTest extends \PHPUnit_Framework_TestCase
 {
 
@@ -17,7 +19,7 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
     {
         $urlValue = 'http://www.phpexcel.net';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink($urlValue);
+        $testInstance = new Hyperlink($urlValue);
 
         $result = $testInstance->getUrl();
         $this->assertEquals($urlValue, $result);
@@ -28,9 +30,9 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
         $initialUrlValue = 'http://www.phpexcel.net';
         $newUrlValue = 'http://github.com/PHPOffice/PHPExcel';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink($initialUrlValue);
+        $testInstance = new Hyperlink($initialUrlValue);
         $result = $testInstance->setUrl($newUrlValue);
-        $this->assertTrue($result instanceof \PHPExcel\Cell\Hyperlink);
+        $this->assertTrue($result instanceof Hyperlink);
 
         $result = $testInstance->getUrl();
         $this->assertEquals($newUrlValue, $result);
@@ -40,7 +42,7 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
     {
         $tooltipValue = 'PHPExcel Web Site';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink(null, $tooltipValue);
+        $testInstance = new Hyperlink(null, $tooltipValue);
 
         $result = $testInstance->getTooltip();
         $this->assertEquals($tooltipValue, $result);
@@ -51,9 +53,9 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
         $initialTooltipValue = 'PHPExcel Web Site';
         $newTooltipValue = 'PHPExcel Repository on Github';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink(null, $initialTooltipValue);
+        $testInstance = new Hyperlink(null, $initialTooltipValue);
         $result = $testInstance->setTooltip($newTooltipValue);
-        $this->assertTrue($result instanceof \PHPExcel\Cell\Hyperlink);
+        $this->assertTrue($result instanceof Hyperlink);
 
         $result = $testInstance->getTooltip();
         $this->assertEquals($newTooltipValue, $result);
@@ -64,7 +66,7 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
         $initialUrlValue = 'http://www.phpexcel.net';
         $newUrlValue = 'sheet://Worksheet1!A1';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink($initialUrlValue);
+        $testInstance = new Hyperlink($initialUrlValue);
         $result = $testInstance->isInternal();
         $this->assertFalse($result);
 
@@ -79,7 +81,7 @@ class HyperlinkTest extends \PHPUnit_Framework_TestCase
         $tooltipValue = 'PHPExcel Web Site';
         $initialExpectedHash = '176f1ec64e84084db814481bd710b6b3';
 
-        $testInstance = new \PHPExcel\Cell\Hyperlink($urlValue, $tooltipValue);
+        $testInstance = new Hyperlink($urlValue, $tooltipValue);
 
         $result = $testInstance->getHashCode();
         $this->assertEquals($initialExpectedHash, $result);
diff --git a/tests/PhpSpreadsheet/CellTest.php b/tests/PhpSpreadsheet/CellTest.php
index 6f45eb2e..0ab07f33 100644
--- a/tests/PhpSpreadsheet/CellTest.php
+++ b/tests/PhpSpreadsheet/CellTest.php
@@ -1,14 +1,12 @@
 <?php
 
-namespace PHPExcel;
+namespace PhpSpreadsheet\Tests;
+
+use PHPExcel\Cell;
+use PHPExcel\Exception;
 
 class CellTest extends \PHPUnit_Framework_TestCase
 {
-
-    public function setUp()
-    {
-    }
-
     /**
      * @dataProvider providerColumnString
      */
@@ -16,7 +14,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','columnIndexFromString'), $args);
+        $result = call_user_func_array(array(Cell::class,'columnIndexFromString'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -29,9 +27,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = 'ABCD';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','columnIndexFromString'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'columnIndexFromString'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Column string index can not be longer than 3 characters');
             return;
         }
@@ -42,9 +40,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = '';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','columnIndexFromString'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'columnIndexFromString'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Column string index can not be empty');
             return;
         }
@@ -58,7 +56,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','stringFromColumnIndex'), $args);
+        $result = call_user_func_array(array(Cell::class,'stringFromColumnIndex'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -74,7 +72,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','coordinateFromString'), $args);
+        $result = call_user_func_array(array(Cell::class,'coordinateFromString'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -87,9 +85,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = 'A1:AI2012';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','coordinateFromString'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'coordinateFromString'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Cell coordinate string can not be a range of cells');
             return;
         }
@@ -100,9 +98,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = '';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','coordinateFromString'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'coordinateFromString'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Cell coordinate can not be zero-length string');
             return;
         }
@@ -113,9 +111,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = 'AI';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','coordinateFromString'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'coordinateFromString'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Invalid cell coordinate '.$cellAddress);
             return;
         }
@@ -129,7 +127,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','absoluteCoordinate'), $args);
+        $result = call_user_func_array(array(Cell::class,'absoluteCoordinate'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -142,9 +140,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = 'A1:AI2012';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','absoluteCoordinate'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'absoluteCoordinate'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Cell coordinate string can not be a range of cells');
             return;
         }
@@ -158,7 +156,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','absoluteReference'), $args);
+        $result = call_user_func_array(array(Cell::class,'absoluteReference'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -171,9 +169,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellAddress = 'A1:AI2012';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','absoluteReference'), $cellAddress);
+            $result = call_user_func(array(Cell::class,'absoluteReference'), $cellAddress);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Cell coordinate string can not be a range of cells');
             return;
         }
@@ -187,7 +185,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','splitRange'), $args);
+        $result = call_user_func_array(array(Cell::class,'splitRange'), $args);
         foreach ($result as $key => $split) {
             if (!is_array($expectedResult[$key])) {
                 $this->assertEquals($expectedResult[$key], $split[0]);
@@ -209,7 +207,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','buildRange'), $args);
+        $result = call_user_func_array(array(Cell::class,'buildRange'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -222,9 +220,9 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $cellRange = '';
         try {
-            $result = call_user_func(array('\\PHPExcel\\Cell','buildRange'), $cellRange);
+            $result = call_user_func(array(Cell::class,'buildRange'), $cellRange);
         } catch (\Exception $e) {
-            $this->assertInstanceOf('\\PHPExcel\\Exception', $e);
+            $this->assertInstanceOf(Exception::class, $e);
             $this->assertEquals($e->getMessage(), 'Range does not contain any information');
             return;
         }
@@ -238,7 +236,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','rangeBoundaries'), $args);
+        $result = call_user_func_array(array(Cell::class,'rangeBoundaries'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -254,7 +252,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','rangeDimension'), $args);
+        $result = call_user_func_array(array(Cell::class,'rangeDimension'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -270,7 +268,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','getRangeBoundaries'), $args);
+        $result = call_user_func_array(array(Cell::class,'getRangeBoundaries'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -286,7 +284,7 @@ class CellTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Cell','extractAllCellReferencesInRange'), $args);
+        $result = call_user_func_array(array(Cell::class,'extractAllCellReferencesInRange'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Chart/DataSeriesValuesTest.php b/tests/PhpSpreadsheet/Chart/DataSeriesValuesTest.php
index 51517ce0..43291558 100644
--- a/tests/PhpSpreadsheet/Chart/DataSeriesValuesTest.php
+++ b/tests/PhpSpreadsheet/Chart/DataSeriesValuesTest.php
@@ -2,6 +2,9 @@
 
 namespace PhpSpreadsheet\Tests\Chart;
 
+use PHPExcel\Chart\DataSeriesValues;
+use PHPExcel\Exception;
+
 class DataSeriesValuesTest extends \PHPUnit_Framework_TestCase
 {
     public function testSetDataType()
@@ -11,21 +14,21 @@ class DataSeriesValuesTest extends \PHPUnit_Framework_TestCase
             'String'
         );
 
-        $testInstance = new \PHPExcel\Chart\DataSeriesValues;
+        $testInstance = new DataSeriesValues;
 
         foreach ($dataTypeValues as $dataTypeValue) {
             $result = $testInstance->setDataType($dataTypeValue);
-            $this->assertTrue($result instanceof \PHPExcel\Chart\DataSeriesValues);
+            $this->assertTrue($result instanceof DataSeriesValues);
         }
     }
 
     public function testSetInvalidDataTypeThrowsException()
     {
-        $testInstance = new \PHPExcel\Chart\DataSeriesValues;
+        $testInstance = new DataSeriesValues;
 
         try {
             $result = $testInstance->setDataType('BOOLEAN');
-        } catch (\PHPExcel\Exception $e) {
+        } catch (Exception $e) {
             $this->assertEquals($e->getMessage(), 'Invalid datatype for chart data series values');
             return;
         }
@@ -36,7 +39,7 @@ class DataSeriesValuesTest extends \PHPUnit_Framework_TestCase
     {
         $dataTypeValue = 'String';
 
-        $testInstance = new \PHPExcel\Chart\DataSeriesValues;
+        $testInstance = new DataSeriesValues;
         $setValue = $testInstance->setDataType($dataTypeValue);
 
         $result = $testInstance->getDataType();
diff --git a/tests/PhpSpreadsheet/Chart/LayoutTest.php b/tests/PhpSpreadsheet/Chart/LayoutTest.php
index c4817e58..23074beb 100644
--- a/tests/PhpSpreadsheet/Chart/LayoutTest.php
+++ b/tests/PhpSpreadsheet/Chart/LayoutTest.php
@@ -2,23 +2,25 @@
 
 namespace PhpSpreadsheet\Tests\Chart;
 
+use PHPExcel\Chart\Layout;
+
 class LayoutTest extends \PHPUnit_Framework_TestCase
 {
     public function testSetLayoutTarget()
     {
         $LayoutTargetValue = 'String';
 
-        $testInstance = new \PHPExcel\Chart\Layout;
+        $testInstance = new Layout;
 
         $result = $testInstance->setLayoutTarget($LayoutTargetValue);
-        $this->assertTrue($result instanceof \PHPExcel\Chart\Layout);
+        $this->assertTrue($result instanceof Layout);
     }
 
     public function testGetLayoutTarget()
     {
         $LayoutTargetValue = 'String';
 
-        $testInstance = new \PHPExcel\Chart\Layout;
+        $testInstance = new Layout;
         $setValue = $testInstance->setLayoutTarget($LayoutTargetValue);
 
         $result = $testInstance->getLayoutTarget();
diff --git a/tests/PhpSpreadsheet/Chart/LegendTest.php b/tests/PhpSpreadsheet/Chart/LegendTest.php
index bd196038..b7ab9a48 100644
--- a/tests/PhpSpreadsheet/Chart/LegendTest.php
+++ b/tests/PhpSpreadsheet/Chart/LegendTest.php
@@ -2,19 +2,21 @@
 
 namespace PhpSpreadsheet\Tests\Chart;
 
+use PHPExcel\Chart\Legend;
+
 class LegendTest extends \PHPUnit_Framework_TestCase
 {
     public function testSetPosition()
     {
         $positionValues = array(
-            \PHPExcel\Chart\Legend::POSITION_RIGHT,
-            \PHPExcel\Chart\Legend::POSITION_LEFT,
-            \PHPExcel\Chart\Legend::POSITION_TOP,
-            \PHPExcel\Chart\Legend::POSITION_BOTTOM,
-            \PHPExcel\Chart\Legend::POSITION_TOPRIGHT,
+            Legend::POSITION_RIGHT,
+            Legend::POSITION_LEFT,
+            Legend::POSITION_TOP,
+            Legend::POSITION_BOTTOM,
+            Legend::POSITION_TOPRIGHT,
         );
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         foreach ($positionValues as $positionValue) {
             $result = $testInstance->setPosition($positionValue);
@@ -24,20 +26,20 @@ class LegendTest extends \PHPUnit_Framework_TestCase
 
     public function testSetInvalidPositionReturnsFalse()
     {
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         $result = $testInstance->setPosition('BottomLeft');
         $this->assertFalse($result);
         //    Ensure that value is unchanged
         $result = $testInstance->getPosition();
-        $this->assertEquals(\PHPExcel\Chart\Legend::POSITION_RIGHT, $result);
+        $this->assertEquals(Legend::POSITION_RIGHT, $result);
     }
 
     public function testGetPosition()
     {
-        $PositionValue = \PHPExcel\Chart\Legend::POSITION_BOTTOM;
+        $PositionValue = Legend::POSITION_BOTTOM;
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
         $setValue = $testInstance->setPosition($PositionValue);
 
         $result = $testInstance->getPosition();
@@ -47,15 +49,15 @@ class LegendTest extends \PHPUnit_Framework_TestCase
     public function testSetPositionXL()
     {
         $positionValues = array(
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_BOTTOM,
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_CORNER,
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_CUSTOM,
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_LEFT,
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_RIGHT,
-            \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_TOP,
+            Legend::XL_LEGEND_POSITION_BOTTOM,
+            Legend::XL_LEGEND_POSITION_CORNER,
+            Legend::XL_LEGEND_POSITION_CUSTOM,
+            Legend::XL_LEGEND_POSITION_LEFT,
+            Legend::XL_LEGEND_POSITION_RIGHT,
+            Legend::XL_LEGEND_POSITION_TOP,
         );
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         foreach ($positionValues as $positionValue) {
             $result = $testInstance->setPositionXL($positionValue);
@@ -65,20 +67,20 @@ class LegendTest extends \PHPUnit_Framework_TestCase
 
     public function testSetInvalidXLPositionReturnsFalse()
     {
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         $result = $testInstance->setPositionXL(999);
         $this->assertFalse($result);
         //    Ensure that value is unchanged
         $result = $testInstance->getPositionXL();
-        $this->assertEquals(\PHPExcel\Chart\Legend::XL_LEGEND_POSITION_RIGHT, $result);
+        $this->assertEquals(Legend::XL_LEGEND_POSITION_RIGHT, $result);
     }
 
     public function testGetPositionXL()
     {
-        $PositionValue = \PHPExcel\Chart\Legend::XL_LEGEND_POSITION_CORNER;
+        $PositionValue = Legend::XL_LEGEND_POSITION_CORNER;
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
         $setValue = $testInstance->setPositionXL($PositionValue);
 
         $result = $testInstance->getPositionXL();
@@ -92,7 +94,7 @@ class LegendTest extends \PHPUnit_Framework_TestCase
             false,
         );
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         foreach ($overlayValues as $overlayValue) {
             $result = $testInstance->setOverlay($overlayValue);
@@ -102,7 +104,7 @@ class LegendTest extends \PHPUnit_Framework_TestCase
 
     public function testSetInvalidOverlayReturnsFalse()
     {
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
 
         $result = $testInstance->setOverlay('INVALID');
         $this->assertFalse($result);
@@ -115,7 +117,7 @@ class LegendTest extends \PHPUnit_Framework_TestCase
     {
         $OverlayValue = true;
 
-        $testInstance = new \PHPExcel\Chart\Legend;
+        $testInstance = new Legend;
         $setValue = $testInstance->setOverlay($OverlayValue);
 
         $result = $testInstance->getOverlay();
diff --git a/tests/PhpSpreadsheet/Custom/Complex.php b/tests/PhpSpreadsheet/Custom/Complex.php
index 6c20c4ae..3b520813 100644
--- a/tests/PhpSpreadsheet/Custom/Complex.php
+++ b/tests/PhpSpreadsheet/Custom/Complex.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Custom;
 
+use PHPExcel\Exception;
+
 class Complex
 {
     private $realPart = 0;
@@ -33,7 +35,7 @@ class Complex
             //    Neither real nor imaginary part, so test to see if we actually have a suffix
             $validComplex = preg_match('/^([\-\+]?)([ij])$/ui', $complexNumber, $complexParts);
             if (!$validComplex) {
-                throw new \PHPExcel\Exception('COMPLEX: Invalid complex number');
+                throw new Exception('COMPLEX: Invalid complex number');
             }
             //    We have a suffix, so set the real to 0, the imaginary to either 1 or -1 (as defined by the sign)
             $imaginary = 1;
diff --git a/tests/PhpSpreadsheet/Reader/XEEValidatorTest.php b/tests/PhpSpreadsheet/Reader/XEEValidatorTest.php
index 9f27c12d..4694ecea 100644
--- a/tests/PhpSpreadsheet/Reader/XEEValidatorTest.php
+++ b/tests/PhpSpreadsheet/Reader/XEEValidatorTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Reader;
 
+use PHPExcel\Reader\BaseReader;
+
 class XEEValidatorTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -10,7 +12,7 @@ class XEEValidatorTest extends \PHPUnit_Framework_TestCase
      */
     public function testInvalidXML($filename)
     {
-        $reader = $this->getMockForAbstractClass('\PHPExcel\Reader\BaseReader');
+        $reader = $this->getMockForAbstractClass(BaseReader::class);
         $expectedResult = 'FAILURE: Should throw an Exception rather than return a value';
         $result = $reader->securityScanFile($filename);
         $this->assertEquals($expectedResult, $result);
@@ -30,7 +32,7 @@ class XEEValidatorTest extends \PHPUnit_Framework_TestCase
      */
     public function testValidXML($filename, $expectedResult)
     {
-        $reader = $this->getMockForAbstractClass('\PHPExcel\Reader\BaseReader');
+        $reader = $this->getMockForAbstractClass(BaseReader::class);
         $result = $reader->securityScanFile($filename);
         $this->assertEquals($expectedResult, $result);
     }
diff --git a/tests/PhpSpreadsheet/ReferenceHelperTest.php b/tests/PhpSpreadsheet/ReferenceHelperTest.php
index 4f25f347..da2a3541 100644
--- a/tests/PhpSpreadsheet/ReferenceHelperTest.php
+++ b/tests/PhpSpreadsheet/ReferenceHelperTest.php
@@ -1,6 +1,8 @@
 <?php
 
-namespace PHPExcel;
+namespace PhpSpreadsheet\Tests;
+
+use PHPExcel\ReferenceHelper;
 
 class ReferenceHelperTest extends \PHPUnit_Framework_TestCase
 {
@@ -24,7 +26,7 @@ class ReferenceHelperTest extends \PHPUnit_Framework_TestCase
             'BZA','BZB','BZZ'
         ];
         shuffle($columnBase);
-        usort($columnBase, array('\\PHPExcel\\ReferenceHelper','columnSort'));
+        usort($columnBase, array(ReferenceHelper::class,'columnSort'));
         foreach ($columnBase as $key => $value) {
             $this->assertEquals($columnExpectedResult[$key], $value);
         }
@@ -46,7 +48,7 @@ class ReferenceHelperTest extends \PHPUnit_Framework_TestCase
         ];
         shuffle($columnBase);
         $columnExpectedResult = array_reverse($columnExpectedResult);
-        usort($columnBase, array('\\PHPExcel\\ReferenceHelper','columnReverseSort'));
+        usort($columnBase, array(ReferenceHelper::class,'columnReverseSort'));
         foreach ($columnBase as $key => $value) {
             $this->assertEquals($columnExpectedResult[$key], $value);
         }
diff --git a/tests/PhpSpreadsheet/SettingsTest.php b/tests/PhpSpreadsheet/SettingsTest.php
index 06161c47..9518cbc6 100644
--- a/tests/PhpSpreadsheet/SettingsTest.php
+++ b/tests/PhpSpreadsheet/SettingsTest.php
@@ -1,6 +1,6 @@
 <?php
 
-namespace PHPExcel;
+namespace PhpSpreadsheet\Tests;
 
 class SettingsTest extends \PHPUnit_Framework_TestCase
 {
diff --git a/tests/PhpSpreadsheet/Shared/CodePageTest.php b/tests/PhpSpreadsheet/Shared/CodePageTest.php
index 0efdff94..e2a3009b 100644
--- a/tests/PhpSpreadsheet/Shared/CodePageTest.php
+++ b/tests/PhpSpreadsheet/Shared/CodePageTest.php
@@ -2,6 +2,9 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\CodePage;
+use PHPExcel\Exception;
+
 class CodePageTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -11,7 +14,7 @@ class CodePageTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\CodePage','numberToName'), $args);
+        $result = call_user_func_array(array(CodePage::class,'numberToName'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -24,8 +27,8 @@ class CodePageTest extends \PHPUnit_Framework_TestCase
     {
         $invalidCodePage = 12345;
         try {
-            $result = call_user_func(array('\PHPExcel\Shared\CodePage','numberToName'), $invalidCodePage);
-        } catch (\PHPExcel\Exception $e) {
+            $result = call_user_func(array(CodePage::class,'numberToName'), $invalidCodePage);
+        } catch (Exception $e) {
             $this->assertEquals($e->getMessage(), 'Unknown codepage: 12345');
             return;
         }
@@ -36,8 +39,8 @@ class CodePageTest extends \PHPUnit_Framework_TestCase
     {
         $unsupportedCodePage = 720;
         try {
-            $result = call_user_func(array('\PHPExcel\Shared\CodePage','numberToName'), $unsupportedCodePage);
-        } catch (\PHPExcel\Exception $e) {
+            $result = call_user_func(array(CodePage::class,'numberToName'), $unsupportedCodePage);
+        } catch (Exception $e) {
             $this->assertEquals($e->getMessage(), 'Code page 720 not supported.');
             return;
         }
diff --git a/tests/PhpSpreadsheet/Shared/DateTest.php b/tests/PhpSpreadsheet/Shared/DateTest.php
index edb13c71..b2b2c083 100644
--- a/tests/PhpSpreadsheet/Shared/DateTest.php
+++ b/tests/PhpSpreadsheet/Shared/DateTest.php
@@ -2,17 +2,19 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\Date;
+
 class DateTest extends \PHPUnit_Framework_TestCase
 {
     public function testSetExcelCalendar()
     {
         $calendarValues = array(
-            \PHPExcel\Shared\Date::CALENDAR_MAC_1904,
-            \PHPExcel\Shared\Date::CALENDAR_WINDOWS_1900,
+            Date::CALENDAR_MAC_1904,
+            Date::CALENDAR_WINDOWS_1900,
         );
 
         foreach ($calendarValues as $calendarValue) {
-            $result = call_user_func(array('\PHPExcel\Shared\Date','setExcelCalendar'), $calendarValue);
+            $result = call_user_func(array(Date::class,'setExcelCalendar'), $calendarValue);
             $this->assertTrue($result);
         }
     }
@@ -20,7 +22,7 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testSetExcelCalendarWithInvalidValue()
     {
         $unsupportedCalendar = '2012';
-        $result = call_user_func(array('\PHPExcel\Shared\Date','setExcelCalendar'), $unsupportedCalendar);
+        $result = call_user_func(array(Date::class,'setExcelCalendar'), $unsupportedCalendar);
         $this->assertFalse($result);
     }
 
@@ -30,8 +32,8 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimeExcelToPHP1900()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_WINDOWS_1900
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_WINDOWS_1900
         );
 
         $args = func_get_args();
@@ -39,7 +41,7 @@ class DateTest extends \PHPUnit_Framework_TestCase
         if ($args[0] < 1) {
             $expectedResult += gmmktime(0, 0, 0);
         }
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date', 'ExcelToPHP'), $args);
+        $result = call_user_func_array(array(Date::class, 'ExcelToPHP'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -54,13 +56,13 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimePHPToExcel1900()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_WINDOWS_1900
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_WINDOWS_1900
         );
 
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','PHPToExcel'), $args);
+        $result = call_user_func_array(array(Date::class,'PHPToExcel'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-5);
     }
 
@@ -75,13 +77,13 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimeFormattedPHPToExcel1900()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_WINDOWS_1900
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_WINDOWS_1900
         );
 
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','formattedPHPToExcel'), $args);
+        $result = call_user_func_array(array(Date::class,'formattedPHPToExcel'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-5);
     }
 
@@ -96,8 +98,8 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimeExcelToPHP1904()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_MAC_1904
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_MAC_1904
         );
 
         $args = func_get_args();
@@ -105,7 +107,7 @@ class DateTest extends \PHPUnit_Framework_TestCase
         if ($args[0] < 1) {
             $expectedResult += gmmktime(0, 0, 0);
         }
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','ExcelToPHP'), $args);
+        $result = call_user_func_array(array(Date::class,'ExcelToPHP'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -120,13 +122,13 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimePHPToExcel1904()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_MAC_1904
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_MAC_1904
         );
 
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','PHPToExcel'), $args);
+        $result = call_user_func_array(array(Date::class,'PHPToExcel'), $args);
         $this->assertEquals($expectedResult, $result, null, 1E-5);
     }
 
@@ -142,7 +144,7 @@ class DateTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','isDateTimeFormatCode'), $args);
+        $result = call_user_func_array(array(Date::class,'isDateTimeFormatCode'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -158,8 +160,8 @@ class DateTest extends \PHPUnit_Framework_TestCase
     public function testDateTimeExcelToPHP1900Timezone()
     {
         $result = call_user_func(
-            array('\PHPExcel\Shared\Date','setExcelCalendar'),
-            \PHPExcel\Shared\Date::CALENDAR_WINDOWS_1900
+            array(Date::class,'setExcelCalendar'),
+            Date::CALENDAR_WINDOWS_1900
         );
 
         $args = func_get_args();
@@ -167,7 +169,7 @@ class DateTest extends \PHPUnit_Framework_TestCase
         if ($args[0] < 1) {
             $expectedResult += gmmktime(0, 0, 0);
         }
-        $result = call_user_func_array(array('\PHPExcel\Shared\Date','ExcelToPHP'), $args);
+        $result = call_user_func_array(array(Date::class,'ExcelToPHP'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Shared/FileTest.php b/tests/PhpSpreadsheet/Shared/FileTest.php
index 46478e6e..89a36596 100644
--- a/tests/PhpSpreadsheet/Shared/FileTest.php
+++ b/tests/PhpSpreadsheet/Shared/FileTest.php
@@ -2,13 +2,15 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\File;
+
 class FileTest extends \PHPUnit_Framework_TestCase
 {
     public function testGetUseUploadTempDirectory()
     {
         $expectedResult = false;
 
-        $result = call_user_func(array('\PHPExcel\Shared\File','getUseUploadTempDirectory'));
+        $result = call_user_func(array(File::class,'getUseUploadTempDirectory'));
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -20,9 +22,9 @@ class FileTest extends \PHPUnit_Framework_TestCase
         );
 
         foreach ($useUploadTempDirectoryValues as $useUploadTempDirectoryValue) {
-            call_user_func(array('\PHPExcel\Shared\File','setUseUploadTempDirectory'), $useUploadTempDirectoryValue);
+            call_user_func(array(File::class,'setUseUploadTempDirectory'), $useUploadTempDirectoryValue);
 
-            $result = call_user_func(array('\PHPExcel\Shared\File','getUseUploadTempDirectory'));
+            $result = call_user_func(array(File::class,'getUseUploadTempDirectory'));
             $this->assertEquals($useUploadTempDirectoryValue, $result);
         }
     }
diff --git a/tests/PhpSpreadsheet/Shared/FontTest.php b/tests/PhpSpreadsheet/Shared/FontTest.php
index ebed03f9..a91516cd 100644
--- a/tests/PhpSpreadsheet/Shared/FontTest.php
+++ b/tests/PhpSpreadsheet/Shared/FontTest.php
@@ -2,25 +2,27 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\Font;
+
 class FontTest extends \PHPUnit_Framework_TestCase
 {
     public function testGetAutoSizeMethod()
     {
-        $expectedResult = \PHPExcel\Shared\Font::AUTOSIZE_METHOD_APPROX;
+        $expectedResult = Font::AUTOSIZE_METHOD_APPROX;
 
-        $result = call_user_func(array('\PHPExcel\Shared\Font','getAutoSizeMethod'));
+        $result = call_user_func(array(Font::class,'getAutoSizeMethod'));
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testSetAutoSizeMethod()
     {
         $autosizeMethodValues = array(
-            \PHPExcel\Shared\Font::AUTOSIZE_METHOD_EXACT,
-            \PHPExcel\Shared\Font::AUTOSIZE_METHOD_APPROX,
+            Font::AUTOSIZE_METHOD_EXACT,
+            Font::AUTOSIZE_METHOD_APPROX,
         );
 
         foreach ($autosizeMethodValues as $autosizeMethodValue) {
-            $result = call_user_func(array('\PHPExcel\Shared\Font','setAutoSizeMethod'), $autosizeMethodValue);
+            $result = call_user_func(array(Font::class,'setAutoSizeMethod'), $autosizeMethodValue);
             $this->assertTrue($result);
         }
     }
@@ -29,7 +31,7 @@ class FontTest extends \PHPUnit_Framework_TestCase
     {
         $unsupportedAutosizeMethod = 'guess';
 
-        $result = call_user_func(array('\PHPExcel\Shared\Font','setAutoSizeMethod'), $unsupportedAutosizeMethod);
+        $result = call_user_func(array(Font::class,'setAutoSizeMethod'), $unsupportedAutosizeMethod);
         $this->assertFalse($result);
     }
 
@@ -40,7 +42,7 @@ class FontTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Font','fontSizeToPixels'), $args);
+        $result = call_user_func_array(array(Font::class,'fontSizeToPixels'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -56,7 +58,7 @@ class FontTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Font','inchSizeToPixels'), $args);
+        $result = call_user_func_array(array(Font::class,'inchSizeToPixels'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -72,7 +74,7 @@ class FontTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\Font','centimeterSizeToPixels'), $args);
+        $result = call_user_func_array(array(Font::class,'centimeterSizeToPixels'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Shared/PasswordHasherTest.php b/tests/PhpSpreadsheet/Shared/PasswordHasherTest.php
index c779a366..21f4a34e 100644
--- a/tests/PhpSpreadsheet/Shared/PasswordHasherTest.php
+++ b/tests/PhpSpreadsheet/Shared/PasswordHasherTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\PasswordHasher;
+
 class PasswordHasherTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -12,7 +14,7 @@ class PasswordHasherTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Shared\PasswordHasher','hashPassword'), $args);
+        $result = call_user_func_array(array(PasswordHasher::class,'hashPassword'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Shared/StringTest.php b/tests/PhpSpreadsheet/Shared/StringTest.php
index 389a8d06..19885efb 100644
--- a/tests/PhpSpreadsheet/Shared/StringTest.php
+++ b/tests/PhpSpreadsheet/Shared/StringTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\StringHelper;
+
 class StringTest extends \PHPUnit_Framework_TestCase
 {
     public function setUp()
@@ -9,18 +11,18 @@ class StringTest extends \PHPUnit_Framework_TestCase
         parent::setUp();
 
         // Reset Currency Code
-        call_user_func(array('\PHPExcel\Shared\StringHelper','setCurrencyCode'), null);
+        call_user_func(array(StringHelper::class,'setCurrencyCode'), null);
     }
 
     public function testGetIsMbStringEnabled()
     {
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getIsMbstringEnabled'));
+        $result = call_user_func(array(StringHelper::class,'getIsMbstringEnabled'));
         $this->assertTrue($result);
     }
 
     public function testGetIsIconvEnabled()
     {
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getIsIconvEnabled'));
+        $result = call_user_func(array(StringHelper::class,'getIsIconvEnabled'));
         $this->assertTrue($result);
     }
 
@@ -29,16 +31,16 @@ class StringTest extends \PHPUnit_Framework_TestCase
         $localeconv = localeconv();
 
         $expectedResult = (!empty($localeconv['decimal_point'])) ? $localeconv['decimal_point'] : ',';
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getDecimalSeparator'));
+        $result = call_user_func(array(StringHelper::class,'getDecimalSeparator'));
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testSetDecimalSeparator()
     {
         $expectedResult = ',';
-        call_user_func(array('\PHPExcel\Shared\StringHelper','setDecimalSeparator'), $expectedResult);
+        call_user_func(array(StringHelper::class,'setDecimalSeparator'), $expectedResult);
 
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getDecimalSeparator'));
+        $result = call_user_func(array(StringHelper::class,'getDecimalSeparator'));
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -47,16 +49,16 @@ class StringTest extends \PHPUnit_Framework_TestCase
         $localeconv = localeconv();
 
         $expectedResult = (!empty($localeconv['thousands_sep'])) ? $localeconv['thousands_sep'] : ',';
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getThousandsSeparator'));
+        $result = call_user_func(array(StringHelper::class,'getThousandsSeparator'));
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testSetThousandsSeparator()
     {
         $expectedResult = ' ';
-        call_user_func(array('\PHPExcel\Shared\StringHelper','setThousandsSeparator'), $expectedResult);
+        call_user_func(array(StringHelper::class,'setThousandsSeparator'), $expectedResult);
 
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getThousandsSeparator'));
+        $result = call_user_func(array(StringHelper::class,'getThousandsSeparator'));
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -64,16 +66,16 @@ class StringTest extends \PHPUnit_Framework_TestCase
     {
         $localeconv = localeconv();
         $expectedResult = (!empty($localeconv['currency_symbol']) ? $localeconv['currency_symbol'] : (!empty($localeconv['int_curr_symbol']) ? $localeconv['int_curr_symbol']: '$'));
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getCurrencyCode'));
+        $result = call_user_func(array(StringHelper::class,'getCurrencyCode'));
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testSetCurrencyCode()
     {
         $expectedResult = '£';
-        call_user_func(array('\PHPExcel\Shared\StringHelper','setCurrencyCode'), $expectedResult);
+        call_user_func(array(StringHelper::class,'setCurrencyCode'), $expectedResult);
 
-        $result = call_user_func(array('\PHPExcel\Shared\StringHelper','getCurrencyCode'));
+        $result = call_user_func(array(StringHelper::class,'getCurrencyCode'));
         $this->assertEquals($expectedResult, $result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Shared/TimeZoneTest.php b/tests/PhpSpreadsheet/Shared/TimeZoneTest.php
index ed0b4852..65f74986 100644
--- a/tests/PhpSpreadsheet/Shared/TimeZoneTest.php
+++ b/tests/PhpSpreadsheet/Shared/TimeZoneTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Shared;
 
+use PHPExcel\Shared\TimeZone;
+
 class TimeZoneTest extends \PHPUnit_Framework_TestCase
 {
     public function testSetTimezone()
@@ -15,7 +17,7 @@ class TimeZoneTest extends \PHPUnit_Framework_TestCase
         );
 
         foreach ($timezoneValues as $timezoneValue) {
-            $result = call_user_func(array('\PHPExcel\Shared\TimeZone','setTimezone'), $timezoneValue);
+            $result = call_user_func(array(TimeZone::class,'setTimezone'), $timezoneValue);
             $this->assertTrue($result);
         }
     }
@@ -23,7 +25,7 @@ class TimeZoneTest extends \PHPUnit_Framework_TestCase
     public function testSetTimezoneWithInvalidValue()
     {
         $unsupportedTimezone = 'Etc/GMT+10';
-        $result = call_user_func(array('\PHPExcel\Shared\TimeZone','setTimezone'), $unsupportedTimezone);
+        $result = call_user_func(array(TimeZone::class,'setTimezone'), $unsupportedTimezone);
         $this->assertFalse($result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Style/ColorTest.php b/tests/PhpSpreadsheet/Style/ColorTest.php
index c16b6ccb..4cf17949 100644
--- a/tests/PhpSpreadsheet/Style/ColorTest.php
+++ b/tests/PhpSpreadsheet/Style/ColorTest.php
@@ -2,6 +2,8 @@
 
 namespace PhpSpreadsheet\Tests\Style;
 
+use PHPExcel\Style\Color;
+
 class ColorTest extends \PHPUnit_Framework_TestCase
 {
     /**
@@ -11,7 +13,7 @@ class ColorTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Style\\Color','getRed'), $args);
+        $result = call_user_func_array(array(Color::class,'getRed'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -27,7 +29,7 @@ class ColorTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Style\\Color','getGreen'), $args);
+        $result = call_user_func_array(array(Color::class,'getGreen'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -43,7 +45,7 @@ class ColorTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\\PHPExcel\\Style\\Color','getBlue'), $args);
+        $result = call_user_func_array(array(Color::class,'getBlue'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -58,7 +60,7 @@ class ColorTest extends \PHPUnit_Framework_TestCase
     public function testChangeBrightness()
     {
         list($args, $expectedResult) = func_get_args();
-        $result = call_user_func_array(array('\\PHPExcel\\Style\\Color','changeBrightness'), $args);
+        $result = call_user_func_array(array(Color::class,'changeBrightness'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Style/NumberFormatDateTest.php b/tests/PhpSpreadsheet/Style/NumberFormatDateTest.php
index 5bfeac78..452f9480 100644
--- a/tests/PhpSpreadsheet/Style/NumberFormatDateTest.php
+++ b/tests/PhpSpreadsheet/Style/NumberFormatDateTest.php
@@ -2,13 +2,16 @@
 
 namespace PhpSpreadsheet\Tests\Style;
 
+use PHPExcel\Shared\StringHelper;
+use PHPExcel\Style\NumberFormat;
+
 class NumberFormatDateTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Shared\StringHelper::setDecimalSeparator('.');
-        \PHPExcel\Shared\StringHelper::setThousandsSeparator(',');
+        StringHelper::setDecimalSeparator('.');
+        StringHelper::setThousandsSeparator(',');
     }
 
     /**
@@ -18,7 +21,7 @@ class NumberFormatDateTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Style\NumberFormat','toFormattedString'), $args);
+        $result = call_user_func_array(array(NumberFormat::class,'toFormattedString'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Style/NumberFormatTest.php b/tests/PhpSpreadsheet/Style/NumberFormatTest.php
index ad192b20..af9b16d6 100644
--- a/tests/PhpSpreadsheet/Style/NumberFormatTest.php
+++ b/tests/PhpSpreadsheet/Style/NumberFormatTest.php
@@ -2,13 +2,15 @@
 
 namespace PhpSpreadsheet\Tests\Style;
 
+use PHPExcel\Shared\StringHelper;
+use PHPExcel\Style\NumberFormat;
 class NumberFormatTest extends \PHPUnit_Framework_TestCase
 {
 
     public function setUp()
     {
-        \PHPExcel\Shared\StringHelper::setDecimalSeparator('.');
-        \PHPExcel\Shared\StringHelper::setThousandsSeparator(',');
+        StringHelper::setDecimalSeparator('.');
+        StringHelper::setThousandsSeparator(',');
     }
 
     /**
@@ -18,7 +20,7 @@ class NumberFormatTest extends \PHPUnit_Framework_TestCase
     {
         $args = func_get_args();
         $expectedResult = array_pop($args);
-        $result = call_user_func_array(array('\PHPExcel\Style\NumberFormat','toFormattedString'), $args);
+        $result = call_user_func_array(array(NumberFormat::class,'toFormattedString'), $args);
         $this->assertEquals($expectedResult, $result);
     }
 
diff --git a/tests/PhpSpreadsheet/Worksheet/AutoFilter/Column/RuleTest.php b/tests/PhpSpreadsheet/Worksheet/AutoFilter/Column/RuleTest.php
index 6939d4ee..5de3876f 100644
--- a/tests/PhpSpreadsheet/Worksheet/AutoFilter/Column/RuleTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/AutoFilter/Column/RuleTest.php
@@ -2,42 +2,44 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet\AutoFilter\Column;
 
+use PHPExcel\Worksheet\AutoFilter\Column;
+
 class RuleTest extends \PHPUnit_Framework_TestCase
 {
-    private $_testAutoFilterRuleObject;
+    private $testAutoFilterRuleObject;
 
-    private $_mockAutoFilterColumnObject;
+    private $mockAutoFilterColumnObject;
 
     public function setUp()
     {
-        $this->_mockAutoFilterColumnObject = $this->getMockBuilder('\PHPExcel\Worksheet\AutoFilter\Column')
+        $this->mockAutoFilterColumnObject = $this->getMockBuilder(Column::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->_mockAutoFilterColumnObject->expects($this->any())
+        $this->mockAutoFilterColumnObject->expects($this->any())
             ->method('testColumnInRange')
             ->will($this->returnValue(3));
 
-        $this->_testAutoFilterRuleObject = new \PHPExcel\Worksheet\AutoFilter\Column\Rule(
-            $this->_mockAutoFilterColumnObject
+        $this->testAutoFilterRuleObject = new Column\Rule(
+            $this->mockAutoFilterColumnObject
         );
     }
 
     public function testGetRuleType()
     {
-        $result = $this->_testAutoFilterRuleObject->getRuleType();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_FILTER, $result);
+        $result = $this->testAutoFilterRuleObject->getRuleType();
+        $this->assertEquals(Column\Rule::AUTOFILTER_RULETYPE_FILTER, $result);
     }
 
     public function testSetRuleType()
     {
-        $expectedResult = \PHPExcel\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP;
+        $expectedResult = Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP;
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterRuleObject->setRuleType($expectedResult);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = $this->testAutoFilterRuleObject->setRuleType($expectedResult);
+        $this->assertInstanceOf(Column\Rule::class, $result);
 
-        $result = $this->_testAutoFilterRuleObject->getRuleType();
+        $result = $this->testAutoFilterRuleObject->getRuleType();
         $this->assertEquals($expectedResult, $result);
     }
 
@@ -46,59 +48,59 @@ class RuleTest extends \PHPUnit_Framework_TestCase
         $expectedResult = 100;
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterRuleObject->setValue($expectedResult);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = $this->testAutoFilterRuleObject->setValue($expectedResult);
+        $this->assertInstanceOf(Column\Rule::class, $result);
 
-        $result = $this->_testAutoFilterRuleObject->getValue();
+        $result = $this->testAutoFilterRuleObject->getValue();
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testGetOperator()
     {
-        $result = $this->_testAutoFilterRuleObject->getOperator();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL, $result);
+        $result = $this->testAutoFilterRuleObject->getOperator();
+        $this->assertEquals(Column\Rule::AUTOFILTER_COLUMN_RULE_EQUAL, $result);
     }
 
     public function testSetOperator()
     {
-        $expectedResult = \PHPExcel\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_COLUMN_RULE_LESSTHAN;
+        $expectedResult = Column\Rule::AUTOFILTER_COLUMN_RULE_LESSTHAN;
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterRuleObject->setOperator($expectedResult);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = $this->testAutoFilterRuleObject->setOperator($expectedResult);
+        $this->assertInstanceOf(Column\Rule::class, $result);
 
-        $result = $this->_testAutoFilterRuleObject->getOperator();
+        $result = $this->testAutoFilterRuleObject->getOperator();
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testSetGrouping()
     {
-        $expectedResult = \PHPExcel\Worksheet\AutoFilter\Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP_MONTH;
+        $expectedResult = Column\Rule::AUTOFILTER_RULETYPE_DATEGROUP_MONTH;
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterRuleObject->setGrouping($expectedResult);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = $this->testAutoFilterRuleObject->setGrouping($expectedResult);
+        $this->assertInstanceOf(Column\Rule::class, $result);
 
-        $result = $this->_testAutoFilterRuleObject->getGrouping();
+        $result = $this->testAutoFilterRuleObject->getGrouping();
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testGetParent()
     {
-        $result = $this->_testAutoFilterRuleObject->getParent();
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterRuleObject->getParent();
+        $this->assertInstanceOf(Column::class, $result);
     }
 
     public function testSetParent()
     {
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterRuleObject->setParent($this->_mockAutoFilterColumnObject);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = $this->testAutoFilterRuleObject->setParent($this->mockAutoFilterColumnObject);
+        $this->assertInstanceOf(Column\Rule::class, $result);
     }
 
     public function testClone()
     {
-        $result = clone $this->_testAutoFilterRuleObject;
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column\Rule', $result);
+        $result = clone $this->testAutoFilterRuleObject;
+        $this->assertInstanceOf(Column\Rule::class, $result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/AutoFilter/ColumnTest.php b/tests/PhpSpreadsheet/Worksheet/AutoFilter/ColumnTest.php
index deed5c39..61776bf5 100644
--- a/tests/PhpSpreadsheet/Worksheet/AutoFilter/ColumnTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/AutoFilter/ColumnTest.php
@@ -2,34 +2,36 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet\AutoFilter;
 
+use PHPExcel\Worksheet\AutoFilter;
+
 class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
 {
-    private $_testInitialColumn = 'H';
+    private $testInitialColumn = 'H';
 
-    private $_testAutoFilterColumnObject;
+    private $testAutoFilterColumnObject;
 
-    private $_mockAutoFilterObject;
+    private $mockAutoFilterObject;
 
     public function setUp()
     {
-        $this->_mockAutoFilterObject = $this->getMockBuilder('\PHPExcel\Worksheet\AutoFilter')
+        $this->mockAutoFilterObject = $this->getMockBuilder(AutoFilter::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->_mockAutoFilterObject->expects($this->any())
+        $this->mockAutoFilterObject->expects($this->any())
             ->method('testColumnInRange')
             ->will($this->returnValue(3));
 
-        $this->_testAutoFilterColumnObject = new \PHPExcel\Worksheet\AutoFilter\Column(
-            $this->_testInitialColumn,
-            $this->_mockAutoFilterObject
+        $this->testAutoFilterColumnObject = new AutoFilter\Column(
+            $this->testInitialColumn,
+            $this->mockAutoFilterObject
         );
     }
 
     public function testGetColumnIndex()
     {
-        $result = $this->_testAutoFilterColumnObject->getColumnIndex();
-        $this->assertEquals($this->_testInitialColumn, $result);
+        $result = $this->testAutoFilterColumnObject->getColumnIndex();
+        $this->assertEquals($this->testInitialColumn, $result);
     }
 
     public function testSetColumnIndex()
@@ -37,39 +39,39 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
         $expectedResult = 'L';
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterColumnObject->setColumnIndex($expectedResult);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterColumnObject->setColumnIndex($expectedResult);
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
 
-        $result = $this->_testAutoFilterColumnObject->getColumnIndex();
+        $result = $this->testAutoFilterColumnObject->getColumnIndex();
         $this->assertEquals($expectedResult, $result);
     }
 
     public function testGetParent()
     {
-        $result = $this->_testAutoFilterColumnObject->getParent();
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter', $result);
+        $result = $this->testAutoFilterColumnObject->getParent();
+        $this->assertInstanceOf(AutoFilter::class, $result);
     }
 
     public function testSetParent()
     {
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterColumnObject->setParent($this->_mockAutoFilterObject);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterColumnObject->setParent($this->mockAutoFilterObject);
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
     }
 
     public function testGetFilterType()
     {
-        $result = $this->_testAutoFilterColumnObject->getFilterType();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER, $result);
+        $result = $this->testAutoFilterColumnObject->getFilterType();
+        $this->assertEquals(AutoFilter\Column::AUTOFILTER_FILTERTYPE_FILTER, $result);
     }
 
     public function testSetFilterType()
     {
-        $result = $this->_testAutoFilterColumnObject->setFilterType(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterColumnObject->setFilterType(AutoFilter\Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER);
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
 
-        $result = $this->_testAutoFilterColumnObject->getFilterType();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER, $result);
+        $result = $this->testAutoFilterColumnObject->getFilterType();
+        $this->assertEquals(AutoFilter\Column::AUTOFILTER_FILTERTYPE_DYNAMICFILTER, $result);
     }
 
     /**
@@ -79,22 +81,22 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
     {
         $expectedResult = 'Unfiltered';
 
-        $result = $this->_testAutoFilterColumnObject->setFilterType($expectedResult);
+        $result = $this->testAutoFilterColumnObject->setFilterType($expectedResult);
     }
 
     public function testGetJoin()
     {
-        $result = $this->_testAutoFilterColumnObject->getJoin();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_OR, $result);
+        $result = $this->testAutoFilterColumnObject->getJoin();
+        $this->assertEquals(AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_OR, $result);
     }
 
     public function testSetJoin()
     {
-        $result = $this->_testAutoFilterColumnObject->setJoin(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterColumnObject->setJoin(AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND);
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
 
-        $result = $this->_testAutoFilterColumnObject->getJoin();
-        $this->assertEquals(\PHPExcel\Worksheet\AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND, $result);
+        $result = $this->testAutoFilterColumnObject->getJoin();
+        $this->assertEquals(AutoFilter\Column::AUTOFILTER_COLUMN_JOIN_AND, $result);
     }
 
     /**
@@ -104,7 +106,7 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
     {
         $expectedResult = 'Neither';
 
-        $result = $this->_testAutoFilterColumnObject->setJoin($expectedResult);
+        $result = $this->testAutoFilterColumnObject->setJoin($expectedResult);
     }
 
     public function testSetAttributes()
@@ -114,8 +116,8 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
                              );
 
         //    Setters return the instance to implement the fluent interface
-        $result = $this->_testAutoFilterColumnObject->setAttributes($attributeSet);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = $this->testAutoFilterColumnObject->setAttributes($attributeSet);
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
     }
 
     public function testGetAttributes()
@@ -124,9 +126,9 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
                                 'maxVal' => 200
                              );
 
-        $this->_testAutoFilterColumnObject->setAttributes($attributeSet);
+        $this->testAutoFilterColumnObject->setAttributes($attributeSet);
 
-        $result = $this->_testAutoFilterColumnObject->getAttributes();
+        $result = $this->testAutoFilterColumnObject->getAttributes();
         $this->assertTrue(is_array($result));
         $this->assertEquals(count($attributeSet), count($result));
     }
@@ -139,8 +141,8 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
 
         foreach ($attributeSet as $attributeName => $attributeValue) {
             //    Setters return the instance to implement the fluent interface
-            $result = $this->_testAutoFilterColumnObject->setAttribute($attributeName, $attributeValue);
-            $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+            $result = $this->testAutoFilterColumnObject->setAttribute($attributeName, $attributeValue);
+            $this->assertInstanceOf(AutoFilter\Column::class, $result);
         }
     }
 
@@ -150,19 +152,19 @@ class AutofilterColumnTest extends \PHPUnit_Framework_TestCase
                                 'maxVal' => 200
                              );
 
-        $this->_testAutoFilterColumnObject->setAttributes($attributeSet);
+        $this->testAutoFilterColumnObject->setAttributes($attributeSet);
 
         foreach ($attributeSet as $attributeName => $attributeValue) {
-            $result = $this->_testAutoFilterColumnObject->getAttribute($attributeName);
+            $result = $this->testAutoFilterColumnObject->getAttribute($attributeName);
             $this->assertEquals($attributeValue, $result);
         }
-        $result = $this->_testAutoFilterColumnObject->getAttribute('nonExistentAttribute');
+        $result = $this->testAutoFilterColumnObject->getAttribute('nonExistentAttribute');
         $this->assertNull($result);
     }
 
     public function testClone()
     {
-        $result = clone $this->_testAutoFilterColumnObject;
-        $this->assertInstanceOf('\PHPExcel\Worksheet\AutoFilter\Column', $result);
+        $result = clone $this->testAutoFilterColumnObject;
+        $this->assertInstanceOf(AutoFilter\Column::class, $result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/AutoFilterTest.php b/tests/PhpSpreadsheet/Worksheet/AutoFilterTest.php
index 710b5e99..8e66e37b 100644
--- a/tests/PhpSpreadsheet/Worksheet/AutoFilterTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/AutoFilterTest.php
@@ -3,6 +3,9 @@
 namespace PhpSpreadsheet\Tests\Worksheet;
 
 use PHPExcel\Worksheet\AutoFilter;
+use PHPExcel\Worksheet\AutoFilter\Column;
+use PHPExcel\Worksheet;
+use PHPExcel\CachedObjectStorage\Memory;
 
 class AutoFilterTest extends \PHPUnit_Framework_TestCase
 {
@@ -12,17 +15,19 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
     private $mockWorksheetObject;
 
+    private $mockCacheController;
+
     public function setUp()
     {
-        $this->mockWorksheetObject = $this->getMockBuilder('\\PHPExcel\\Worksheet')
+        $this->mockWorksheetObject = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
-        $this->_mockCacheController = $this->getMockBuilder('\\PHPExcel\\CachedObjectStorage\\Memory')
+        $this->mockCacheController = $this->getMockBuilder(Memory::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->mockWorksheetObject->expects($this->any())
             ->method('getCellCacheController')
-            ->will($this->returnValue($this->_mockCacheController));
+            ->will($this->returnValue($this->mockCacheController));
 
         $this->testAutoFilterObject = new AutoFilter(
             $this->testInitialRange,
@@ -42,14 +47,14 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
     public function testGetParent()
     {
         $result = $this->testAutoFilterObject->getParent();
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet', $result);
+        $this->assertInstanceOf(Worksheet::class, $result);
     }
 
     public function testSetParent()
     {
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setParent($this->mockWorksheetObject);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
     }
 
     public function testGetRange()
@@ -71,7 +76,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         foreach ($ranges as $actualRange => $fullRange) {
             //  Setters return the instance to implement the fluent interface
             $result = $this->testAutoFilterObject->setRange($fullRange);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+            $this->assertInstanceOf(AutoFilter::class, $result);
 
             //  Result should be the new autofilter range
             $result = $this->testAutoFilterObject->getRange();
@@ -85,7 +90,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setRange();
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
 
         //  Result should be a clear range
         $result = $this->testAutoFilterObject->getRange();
@@ -142,7 +147,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setColumn($expectedResult);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
 
         $result = $this->testAutoFilterObject->getColumns();
         //  Result should be an array of \PHPExcel\Worksheet\AutoFilter\Column
@@ -150,7 +155,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         $this->assertInternalType('array', $result);
         $this->assertEquals(1, count($result));
         $this->assertArrayHasKey($expectedResult, $result);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result[$expectedResult]);
+        $this->assertInstanceOf(Column::class, $result[$expectedResult]);
     }
 
     /**
@@ -170,7 +175,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setColumn($columnObject);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
 
         $result = $this->testAutoFilterObject->getColumns();
         //  Result should be an array of \PHPExcel\Worksheet\AutoFilter\Column
@@ -178,7 +183,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         $this->assertInternalType('array', $result);
         $this->assertEquals(1, count($result));
         $this->assertArrayHasKey($expectedResult, $result);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result[$expectedResult]);
+        $this->assertInstanceOf(Column::class, $result[$expectedResult]);
     }
 
     /**
@@ -218,7 +223,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(count($columnIndexes), count($result));
         foreach ($columnIndexes as $columnIndex) {
             $this->assertArrayHasKey($columnIndex, $result);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result[$columnIndex]);
+            $this->assertInstanceOf(Column::class, $result[$columnIndex]);
         }
     }
 
@@ -234,7 +239,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         //    get a \PHPExcel\Worksheet\AutoFilter\Column object returned
         foreach ($columnIndexes as $columnIndex) {
             $result = $this->testAutoFilterObject->getColumn($columnIndex);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result);
+            $this->assertInstanceOf(Column::class, $result);
         }
     }
 
@@ -250,7 +255,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         //    get a \PHPExcel\Worksheet\AutoFilter\Column object returned
         foreach ($columnIndexes as $columnIndex => $columnID) {
             $result = $this->testAutoFilterObject->getColumnByOffset($columnIndex);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result);
+            $this->assertInstanceOf(Column::class, $result);
             $this->assertEquals($result->getColumnIndex(), $columnID);
         }
     }
@@ -260,7 +265,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         //  If we request a specific column by its column ID, we should
         //    get a \PHPExcel\Worksheet\AutoFilter\Column object returned
         $result = $this->testAutoFilterObject->getColumn('K');
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter\\Column', $result);
+        $this->assertInstanceOf(Column::class, $result);
     }
 
     /**
@@ -284,7 +289,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setRange();
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
 
         //  Range should be cleared
         $result = $this->testAutoFilterObject->getRange();
@@ -313,7 +318,7 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
 
         //  Setters return the instance to implement the fluent interface
         $result = $this->testAutoFilterObject->setRange($expectedResult);
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
 
         //  Range should be correctly set
         $result = $this->testAutoFilterObject->getRange();
@@ -335,6 +340,6 @@ class AutoFilterTest extends \PHPUnit_Framework_TestCase
         }
 
         $result = clone $this->testAutoFilterObject;
-        $this->assertInstanceOf('\\PHPExcel\\Worksheet\\AutoFilter', $result);
+        $this->assertInstanceOf(AutoFilter::class, $result);
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/CellCollectionTest.php b/tests/PhpSpreadsheet/Worksheet/CellCollectionTest.php
index 83bfcd3a..92690c19 100644
--- a/tests/PhpSpreadsheet/Worksheet/CellCollectionTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/CellCollectionTest.php
@@ -2,25 +2,23 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\CachedObjectStorageFactory;
+use PHPExcel\Spreadsheet;
+
 class CellCollectionTest extends \PHPUnit_Framework_TestCase
 {
-
-    public function setUp()
-    {
-    }
-
     public function testCacheLastCell()
     {
-        $methods = \PHPExcel\CachedObjectStorageFactory::getCacheStorageMethods();
+        $methods = CachedObjectStorageFactory::getCacheStorageMethods();
         foreach ($methods as $method) {
-            \PHPExcel\CachedObjectStorageFactory::initialize($method);
-            $workbook = new \PHPExcel\Spreadsheet();
+            CachedObjectStorageFactory::initialize($method);
+            $workbook = new Spreadsheet();
             $cells = ['A1', 'A2'];
             $worksheet = $workbook->getActiveSheet();
             $worksheet->setCellValue('A1', 1);
             $worksheet->setCellValue('A2', 2);
             $this->assertEquals($cells, $worksheet->getCellCollection(), "Cache method \"$method\".");
-            \PHPExcel\CachedObjectStorageFactory::finalize();
+            CachedObjectStorageFactory::finalize();
         }
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/ColumnCellIteratorTest.php b/tests/PhpSpreadsheet/Worksheet/ColumnCellIteratorTest.php
index a25492b2..b840bd7f 100644
--- a/tests/PhpSpreadsheet/Worksheet/ColumnCellIteratorTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/ColumnCellIteratorTest.php
@@ -3,6 +3,8 @@
 namespace PhpSpreadsheet\Tests\Worksheet;
 
 use PHPExcel\Worksheet\ColumnCellIterator;
+use PHPExcel\Cell;
+use PHPExcel\Worksheet;
 
 class ColumnCellIteratorTest extends \PHPUnit_Framework_TestCase
 {
@@ -11,11 +13,11 @@ class ColumnCellIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockCell = $this->getMockBuilder('\\PHPExcel\\Cell')
+        $this->mockCell = $this->getMockBuilder(Cell::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->mockWorksheet = $this->getMockBuilder('\\PHPExcel\\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -36,7 +38,7 @@ class ColumnCellIteratorTest extends \PHPUnit_Framework_TestCase
 
         foreach ($iterator as $key => $ColumnCell) {
             $this->assertEquals($ColumnCellIndexResult++, $key);
-            $this->assertInstanceOf('\\PHPExcel\\Cell', $ColumnCell);
+            $this->assertInstanceOf(Cell::class, $ColumnCell);
         }
     }
 
@@ -48,7 +50,7 @@ class ColumnCellIteratorTest extends \PHPUnit_Framework_TestCase
 
         foreach ($iterator as $key => $ColumnCell) {
             $this->assertEquals($ColumnCellIndexResult++, $key);
-            $this->assertInstanceOf('\\PHPExcel\\Cell', $ColumnCell);
+            $this->assertInstanceOf(Cell::class, $ColumnCell);
         }
     }
 
diff --git a/tests/PhpSpreadsheet/Worksheet/ColumnIteratorTest.php b/tests/PhpSpreadsheet/Worksheet/ColumnIteratorTest.php
index 14c23fc3..8ebc26e1 100644
--- a/tests/PhpSpreadsheet/Worksheet/ColumnIteratorTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/ColumnIteratorTest.php
@@ -2,7 +2,9 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\Worksheet;
 use PHPExcel\Worksheet\ColumnIterator;
+use PHPExcel\Worksheet\Column;
 
 class ColumnIteratorTest extends \PHPUnit_Framework_TestCase
 {
@@ -11,11 +13,11 @@ class ColumnIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockColumn = $this->getMockBuilder('\\PHPExcel\\Worksheet\\Column')
+        $this->mockColumn = $this->getMockBuilder(Column::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->mockWorksheet = $this->getMockBuilder('\\PHPExcel\\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -36,7 +38,7 @@ class ColumnIteratorTest extends \PHPUnit_Framework_TestCase
 
         foreach ($iterator as $key => $column) {
             $this->assertEquals($columnIndexResult++, $key);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\Column', $column);
+            $this->assertInstanceOf(Column::class, $column);
         }
     }
 
@@ -48,7 +50,7 @@ class ColumnIteratorTest extends \PHPUnit_Framework_TestCase
 
         foreach ($iterator as $key => $column) {
             $this->assertEquals($columnIndexResult++, $key);
-            $this->assertInstanceOf('\\PHPExcel\\Worksheet\\Column', $column);
+            $this->assertInstanceOf(Column::class, $column);
         }
     }
 
diff --git a/tests/PhpSpreadsheet/Worksheet/RowCellIteratorTest.php b/tests/PhpSpreadsheet/Worksheet/RowCellIteratorTest.php
index eed9e2e6..9e09476b 100644
--- a/tests/PhpSpreadsheet/Worksheet/RowCellIteratorTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/RowCellIteratorTest.php
@@ -2,6 +2,10 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\Worksheet;
+use PHPExcel\Cell;
+use PHPExcel\Worksheet\RowCellIterator;
+
 class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
@@ -9,11 +13,11 @@ class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockCell = $this->getMockBuilder('PHPExcel_Cell')
+        $this->mockCell = $this->getMockBuilder(Cell::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->mockWorksheet = $this->getMockBuilder('\PHPExcel\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -28,32 +32,32 @@ class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function testIteratorFullRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowCellIterator($this->mockWorksheet);
+        $iterator = new RowCellIterator($this->mockWorksheet);
         $RowCellIndexResult = 'A';
         $this->assertEquals($RowCellIndexResult, $iterator->key());
-        
+
         foreach ($iterator as $key => $RowCell) {
             $this->assertEquals($RowCellIndexResult++, $key);
-            $this->assertInstanceOf('PHPExcel_Cell', $RowCell);
+            $this->assertInstanceOf(Cell::class, $RowCell);
         }
     }
 
     public function testIteratorStartEndRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
+        $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $RowCellIndexResult = 'B';
         $this->assertEquals($RowCellIndexResult, $iterator->key());
-        
+
         foreach ($iterator as $key => $RowCell) {
             $this->assertEquals($RowCellIndexResult++, $key);
-            $this->assertInstanceOf('PHPExcel_Cell', $RowCell);
+            $this->assertInstanceOf(Cell::class, $RowCell);
         }
     }
 
     public function testIteratorSeekAndPrev()
     {
         $ranges = range('A', 'E');
-        $iterator = new \PHPExcel\Worksheet\RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
+        $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $RowCellIndexResult = 'D';
         $iterator->seek('D');
         $this->assertEquals($RowCellIndexResult, $iterator->key());
@@ -70,7 +74,7 @@ class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testSeekOutOfRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
+        $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $iterator->seek(1);
     }
 
@@ -79,7 +83,7 @@ class RowCellIteratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testPrevOutOfRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
+        $iterator = new RowCellIterator($this->mockWorksheet, 2, 'B', 'D');
         $iterator->prev();
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/RowIteratorTest.php b/tests/PhpSpreadsheet/Worksheet/RowIteratorTest.php
index e532a65c..dcb81391 100644
--- a/tests/PhpSpreadsheet/Worksheet/RowIteratorTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/RowIteratorTest.php
@@ -2,6 +2,10 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\Worksheet\RowIterator;
+use PHPExcel\Worksheet;
+use PHPExcel\Worksheet\Row;
+
 class RowIteratorTest extends \PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
@@ -9,11 +13,11 @@ class RowIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockRow = $this->getMockBuilder('\PHPExcel\Worksheet\Row')
+        $this->mockRow = $this->getMockBuilder(Row::class)
             ->disableOriginalConstructor()
             ->getMock();
 
-        $this->mockWorksheet = $this->getMockBuilder('\PHPExcel\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
 
@@ -28,31 +32,31 @@ class RowIteratorTest extends \PHPUnit_Framework_TestCase
 
     public function testIteratorFullRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowIterator($this->mockWorksheet);
+        $iterator = new RowIterator($this->mockWorksheet);
         $rowIndexResult = 1;
         $this->assertEquals($rowIndexResult, $iterator->key());
-        
+
         foreach ($iterator as $key => $row) {
             $this->assertEquals($rowIndexResult++, $key);
-            $this->assertInstanceOf('\PHPExcel\Worksheet\Row', $row);
+            $this->assertInstanceOf(Row::class, $row);
         }
     }
 
     public function testIteratorStartEndRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowIterator($this->mockWorksheet, 2, 4);
+        $iterator = new RowIterator($this->mockWorksheet, 2, 4);
         $rowIndexResult = 2;
         $this->assertEquals($rowIndexResult, $iterator->key());
-        
+
         foreach ($iterator as $key => $row) {
             $this->assertEquals($rowIndexResult++, $key);
-            $this->assertInstanceOf('\PHPExcel\Worksheet\Row', $row);
+            $this->assertInstanceOf(Row::class, $row);
         }
     }
 
     public function testIteratorSeekAndPrev()
     {
-        $iterator = new \PHPExcel\Worksheet\RowIterator($this->mockWorksheet, 2, 4);
+        $iterator = new RowIterator($this->mockWorksheet, 2, 4);
         $columnIndexResult = 4;
         $iterator->seek(4);
         $this->assertEquals($columnIndexResult, $iterator->key());
@@ -68,7 +72,7 @@ class RowIteratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testSeekOutOfRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowIterator($this->mockWorksheet, 2, 4);
+        $iterator = new RowIterator($this->mockWorksheet, 2, 4);
         $iterator->seek(1);
     }
 
@@ -77,7 +81,7 @@ class RowIteratorTest extends \PHPUnit_Framework_TestCase
      */
     public function testPrevOutOfRange()
     {
-        $iterator = new \PHPExcel\Worksheet\RowIterator($this->mockWorksheet, 2, 4);
+        $iterator = new RowIterator($this->mockWorksheet, 2, 4);
         $iterator->prev();
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/WorksheetColumnTest.php b/tests/PhpSpreadsheet/Worksheet/WorksheetColumnTest.php
index 356bd727..85810272 100644
--- a/tests/PhpSpreadsheet/Worksheet/WorksheetColumnTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/WorksheetColumnTest.php
@@ -2,6 +2,10 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\Worksheet;
+use PHPExcel\Worksheet\Column;
+use PHPExcel\Worksheet\ColumnCellIterator;
+
 class WorksheetColumnTest extends \PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
@@ -9,7 +13,7 @@ class WorksheetColumnTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockWorksheet = $this->getMockBuilder('\PHPExcel\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->mockWorksheet->expects($this->any())
@@ -20,24 +24,24 @@ class WorksheetColumnTest extends \PHPUnit_Framework_TestCase
 
     public function testInstantiateColumnDefault()
     {
-        $column = new \PHPExcel\Worksheet\Column($this->mockWorksheet);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\Column', $column);
+        $column = new Column($this->mockWorksheet);
+        $this->assertInstanceOf(Column::class, $column);
         $columnIndex = $column->getColumnIndex();
         $this->assertEquals('A', $columnIndex);
     }
 
     public function testInstantiateColumnSpecified()
     {
-        $column = new \PHPExcel\Worksheet\Column($this->mockWorksheet, 'E');
-        $this->assertInstanceOf('\PHPExcel\Worksheet\Column', $column);
+        $column = new Column($this->mockWorksheet, 'E');
+        $this->assertInstanceOf(Column::class, $column);
         $columnIndex = $column->getColumnIndex();
         $this->assertEquals('E', $columnIndex);
     }
 
     public function testGetCellIterator()
     {
-        $column = new \PHPExcel\Worksheet\Column($this->mockWorksheet);
+        $column = new Column($this->mockWorksheet);
         $cellIterator = $column->getCellIterator();
-        $this->assertInstanceOf('\PHPExcel\Worksheet\ColumnCellIterator', $cellIterator);
+        $this->assertInstanceOf(ColumnCellIterator::class, $cellIterator);
     }
 }
diff --git a/tests/PhpSpreadsheet/Worksheet/WorksheetRowTest.php b/tests/PhpSpreadsheet/Worksheet/WorksheetRowTest.php
index 5f241158..1bd90830 100644
--- a/tests/PhpSpreadsheet/Worksheet/WorksheetRowTest.php
+++ b/tests/PhpSpreadsheet/Worksheet/WorksheetRowTest.php
@@ -2,6 +2,10 @@
 
 namespace PhpSpreadsheet\Tests\Worksheet;
 
+use PHPExcel\Worksheet;
+use PHPExcel\Worksheet\Row;
+use PHPExcel\Worksheet\RowCellIterator;
+
 class WorksheetRowTest extends \PHPUnit_Framework_TestCase
 {
     public $mockWorksheet;
@@ -9,7 +13,7 @@ class WorksheetRowTest extends \PHPUnit_Framework_TestCase
 
     public function setUp()
     {
-        $this->mockWorksheet = $this->getMockBuilder('\PHPExcel\Worksheet')
+        $this->mockWorksheet = $this->getMockBuilder(Worksheet::class)
             ->disableOriginalConstructor()
             ->getMock();
         $this->mockWorksheet->expects($this->any())
@@ -20,24 +24,24 @@ class WorksheetRowTest extends \PHPUnit_Framework_TestCase
 
     public function testInstantiateRowDefault()
     {
-        $row = new \PHPExcel\Worksheet\Row($this->mockWorksheet);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\Row', $row);
+        $row = new Row($this->mockWorksheet);
+        $this->assertInstanceOf(Row::class, $row);
         $rowIndex = $row->getRowIndex();
         $this->assertEquals(1, $rowIndex);
     }
 
     public function testInstantiateRowSpecified()
     {
-        $row = new \PHPExcel\Worksheet\Row($this->mockWorksheet, 5);
-        $this->assertInstanceOf('\PHPExcel\Worksheet\Row', $row);
+        $row = new Row($this->mockWorksheet, 5);
+        $this->assertInstanceOf(Row::class, $row);
         $rowIndex = $row->getRowIndex();
         $this->assertEquals(5, $rowIndex);
     }
 
     public function testGetCellIterator()
     {
-        $row = new \PHPExcel\Worksheet\Row($this->mockWorksheet);
+        $row = new Row($this->mockWorksheet);
         $cellIterator = $row->getCellIterator();
-        $this->assertInstanceOf('\PHPExcel\Worksheet\RowCellIterator', $cellIterator);
+        $this->assertInstanceOf(RowCellIterator::class, $cellIterator);
     }
 }