Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/soh-works/www/websoket-sample/vendor/ratchet/rfc6455/tests/unit/Messaging/MessageTest.php:12 Stack trace: #0 {main} thrown in /home/soh-works/www/websoket-sample/vendor/ratchet/rfc6455/tests/unit/Messaging/MessageTest.php on line 12