public static function main() { $mediator = new ConcreteMediator(); $c1 = new Colleague1($mediator); $c2 = new Colleague2($mediator); $mediator->setColleagues($c1, $c2); $c1->send("Hi, Colleague 2, I'm Colleague 1"); $c2->send("Hi, Colleague 1, I'm Colleague 2"); }