protected boolean isEmptyCluster(Hashtable processed, int x, int y, int z)
	{
		for (final Enumeration e = processed.elements(); e.hasMoreElements(); )
		{
			final GrinderRoom room = (GrinderRoom) e.nextElement();
			if ( ( ( (room.xy[0] > x - CLUSTERSIZE) && (room.xy[0] < x + CLUSTERSIZE))
				  && ( (room.xy[1] > y - CLUSTERSIZE) && (room.xy[1] < y + CLUSTERSIZE)))
				|| ( (room.xy[0] == x) && (room.xy[1] == y)) && (room.z == z))
				return false;
		}
		return true;
	}