Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/wittyly/public_html/live/hr-witty/vendor/sebastian/diff/tests/Exception/InvalidArgumentExceptionTest.php:18 Stack trace: #0 {main} thrown in /home/wittyly/public_html/live/hr-witty/vendor/sebastian/diff/tests/Exception/InvalidArgumentExceptionTest.php on line 18