Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/www/whatsmark.edgt.me/vendor/phpoffice/math/tests/Math/Element/SuperscriptTest.php:11 Stack trace: #0 {main} thrown in /home/www/whatsmark.edgt.me/vendor/phpoffice/math/tests/Math/Element/SuperscriptTest.php on line 11