Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /opt/lampp/htdocs/msjasset/vendor/phpoffice/math/tests/Math/Writer/WriterTestCase.php:11 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/msjasset/vendor/phpoffice/math/tests/Math/Writer/WriterTestCase.php on line 11