public void AddEventListener(OnEventReceived onEventReceived)
        {
            if (lastEventCallback != null)
            {
                PhotonNetwork.OnEventCall -= lastEventCallback;
            }

            lastEventCallback          = delegate(byte eventCode, object content, int senderId) { onEventReceived(eventCode, content); };
            PhotonNetwork.OnEventCall += lastEventCallback;
        }
        public void AddEventListener(OnEventReceived onEventReceived)
        {
            RemoveEventListener();

            // save callback we know how to de-register it
            _lastEventCallback = (Byte eventCode, Object content, Int32 senderId) => onEventReceived(eventCode, content);

            // attach callback
            PhotonNetwork.OnEventCall += _lastEventCallback;
        }