result = mBotListeners.add(listener);
HashSet clone = (HashSet)mBotListeners.clone(); result = clone.add(listener); mBotListeners = clone;
	public boolean addBotListener(BotListener listener)	{		if (null == listener)	throw new IllegalArgumentException("listener can't be null.");		boolean result = false;				synchronized (mBotListenersMonitor)		{			if (!mBotListeners.contains(listener))			{				result = mBotListeners.add(listener);			}			else			{				result = true;			}		}				assert true == mBotListeners.contains(listener);				return result;	}