Fatal error: Uncaught Error: Class 'PHPUnit\Framework\Constraint\Constraint' not found in /opt/lampp/htdocs/vendor/symfony/http-foundation/Test/Constraint/ResponseIsSuccessful.php:17 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/vendor/symfony/http-foundation/Test/Constraint/ResponseIsSuccessful.php on line 17