PhpSpreadsheet/tests/data/Calculation/TextData/T.php

<?php

return [
    [
        123456.789,
        null,
    ],
    [
        '123456.789',
        '123456.789',
    ],
    [
        'Mark Baker',
        'Mark Baker',
    ],
    [
        null,
        null,
    ],
    [
        true,
        null,
    ],
];