Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /opt/lampp/htdocs/us/vendor/hanneskod/classtools/tests/Loader/ClassLoaderTest.php:6 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/us/vendor/hanneskod/classtools/tests/Loader/ClassLoaderTest.php on line 6