/**
* Creates a new EventEmittingStateMachine instance,
* by either using a given event emitter or otherwise creating it's own.
*
* @param string $name
* @param array $states
* @param array $transitions
* @param EventEmitterInterface $event_emitter
*/
public function __construct($name, array $states, array $transitions, EventEmitterInterface $event_emitter = null)
{
parent::__construct($name, $states, $transitions);
$this->event_emitter = $event_emitter ?: new EventEmitter();
}
