protected function getListeners($eventName)
    {
        if (isset($this->listeners[$eventName])) {
            return $this->listeners[$eventName];
        }
        return null;
    }
protected function getListeners($eventName)
    {
        if (isset($this->listeners[$eventName])) {
            return $this->listeners[$eventName];
        }
        return null;
    }
protected function getListeners ( $ eventName ) { if ( isset ( $ this -> listeners [ $ eventName ] ) ) { return $ this -> listeners [ $ eventName ] ; } return null ; }
Gets all registered listeners for an event name.

@param   string  $eventName
@return  array|null
Gets all registered listeners for an event name .