Fatal error: Uncaught Error: Class "Masterminds\HTML5\Tests\TestCase" not found in /var/www/html/vendor/masterminds/html5/test/HTML5/Serializer/OutputRulesTest.php:9 Stack trace: #0 {main} thrown in /var/www/html/vendor/masterminds/html5/test/HTML5/Serializer/OutputRulesTest.php on line 9