Online PHP editor | output for GgXXV

<?php interface VisitorInterface { } interface SerializeVisitorInterface extends VisitorInterface { public function visitSomething(); } class SerializeVisitor implements SerializeVisitorInterface { public function visitSomething() { echo 'Hi something'; } } class BaseEvent { protected $visitor; public function getVisitor(): VisitorInterface { return $this->visitor; } } class SerializeEvent extends BaseEvent { public function __construct() { $this->visitor = new SerializeVisitor(); } public function getVisitor(): SerializeVisitorInterface { return $this->visitor; } } $event = new SerializeEvent(); $event->getVisitor()->visitSomething();