function it_should_register_event_listeners(Machine $machine)
{
$closure = function () {
};
$machine->listen('event', $closure)->shouldBeCalled();
$this->setMachine($machine);
$this->listen('event', $closure);
}
/**
* @param $event
* @param $callback
*/
public function listen($event, $callback)
{
$this->boundEvents[] = $event;
$this->machine->listen($event, $callback);
}