Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /opt/lampp/htdocs/us/vendor/sebastian/diff/tests/Output/Integration/StrictUnifiedDiffOutputBuilderIntegrationTest.php:27 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/us/vendor/sebastian/diff/tests/Output/Integration/StrictUnifiedDiffOutputBuilderIntegrationTest.php on line 27