Online PHP editor | output for cSimO

<?php interface Concrete { public $a = null; protected function foo(); } class Bar { } abstract class AbsConcrete implements Concrete { abstract protected function foo(); } class Customer extends AbsConcrete { public function init() { echo "init\n"; } public function foo( Bar $me = null, Bar $lala = null ) { echo "foo\n"; } } $customer = new Customer; $customer->init(); $customer->foo( new Bar, new Bar );