Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /opt/lampp/htdocs/restaurante.apirest/vendor/ratchet/rfc6455/tests/unit/Messaging/MessageTest.php:12 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/restaurante.apirest/vendor/ratchet/rfc6455/tests/unit/Messaging/MessageTest.php on line 12