result = mServerListeners.remove(listener);
HashSet clone = (HashSet)mServerListeners.clone(); result = clone.remove(listener); mServerListeners = clone;
	public boolean removeServerListener(ServerListener listener)	{		if (null == listener)	throw new IllegalArgumentException("listener can't be null.");        boolean result = false;				synchronized (mServerListenersMonitor)		{			result = mServerListeners.remove(listener);		}				assert false == mServerListeners.contains(listener);				return result;	}