code: public Image getTileImage(int x, int y, int layerIndex) {
  		Layer layer = (Layer) layers.get(layerIndex);
  
  		int tileSetIndex = layer.data[x][y][0];
  		if ((tileSetIndex >= 0) && (tileSetIndex < tileSets.size())) {
  			TileSet tileSet = (TileSet) tileSets.get(tileSetIndex);
  
  			int sheetX = tileSet.getTileX(layer.data[x][y][1]);
  			int sheetY = tileSet.getTileY(layer.data[x][y][1]);
  
  			return tileSet.tiles.getSprite(sheetX, sheetY);
  		}
  
  		return null;
  	}
docs: Gets the Image used to draw the tile at the given x and y coordinates.
  
  @param x
  The x coordinate of the tile whose image should be retrieved
  @param y
  The y coordinate of the tile whose image should be retrieved
  @param layerIndex
  The index of the layer on which the tile whose image should be
  retrieve exists
  @return The image used to draw the specified tile or null if there is no
  image for the specified tile.