public function addListenerId($listenerId)
    {
        if (null !== $this->getListenerId($listenerId)) {
            return;
        }
        
        $this->listeners[$listenerId] = $listenerId;
    }
public function addListenerId($listenerId)
    {
        if (null !== $this->getListenerId($listenerId)) {
            return;
        }
        
        $this->listeners[$listenerId] = $listenerId;
    }
public function addListenerId ( $ listenerId ) { if ( null !== $ this -> getListenerId ( $ listenerId ) ) { return ; } $ this -> listeners [ $ listenerId ] = $ listenerId ; }
Adds the listener id to the collections

@param string $listenerId
Adds the listener id to the collections