Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in D:\xampp\htdocs\bred-web-app\vendor\filp\whoops\tests\Whoops\Util\SystemFacadeTest.php:6 Stack trace: #0 {main} thrown in D:\xampp\htdocs\bred-web-app\vendor\filp\whoops\tests\Whoops\Util\SystemFacadeTest.php on line 6