Fatal error: Uncaught Error: Class "EasyRdf\Serialiser" not found in /var/www/html/vendor/sweetrdf/easyrdf/test/MockClass/Serialiser/MockSerialiser.php:19 Stack trace: #0 {main} thrown in /var/www/html/vendor/sweetrdf/easyrdf/test/MockClass/Serialiser/MockSerialiser.php on line 19