Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in E:\xampp\htdocs\vendor\symfony\http-foundation\Tests\Session\Attribute\AttributeBagTest.php:22 Stack trace: #0 {main} thrown in E:\xampp\htdocs\vendor\symfony\http-foundation\Tests\Session\Attribute\AttributeBagTest.php on line 22