void _OnBroadcastMessageReceived(string arg) {
		Debug.Log ("OnBroadcastMessageReceived: " + arg);
		if (sendbirdResponder != null) {
			BroadcastMessage message = new BroadcastMessage(arg);
			sendbirdResponder.OnBroadcastMessageReceived(message);
		}
	}
	public abstract void OnBroadcastMessageReceived (BroadcastMessage message);