public static ProtocolException throwInaccessibleTileException(String direction, Tile theTile){
	if(theTile == null){
	    return new ProtocolException("Invalid move: tile " + direction
					 + " is not accessible (outside of map)");
	}
	else {
	    return new ProtocolException("Invalid move: " + theTile.tileType + " tile is not accessible");
	}
    }