public function addEntityChangedListener(EntityChangedListenerInterface $listener)
    {
        if (!$this->listeners->hasItem($listener)) {
            $this->listeners->push($listener);
        }
    }
public function addEntityChangedListener(EntityChangedListenerInterface $listener)
    {
        if (!$this->listeners->hasItem($listener)) {
            $this->listeners->push($listener);
        }
    }
public function addEntityChangedListener ( EntityChangedListenerInterface $ listener ) { if ( ! $ this -> listeners -> hasItem ( $ listener ) ) { $ this -> listeners -> push ( $ listener ) ; } }
Attaches the given entity-changed listener.

@param EntityChangedListenerInterface $listener
Attaches the given entity - changed listener .