Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in C:\xampp\htdocs\plugins\Symfony\Component\Notifier\Test\TransportFactoryTestCase.php:27 Stack trace: #0 {main} thrown in C:\xampp\htdocs\plugins\Symfony\Component\Notifier\Test\TransportFactoryTestCase.php on line 27