code: public TileBasedLayer createLayer(String id, TileConfiguration conf, String url) {
  		List<String> urls = new ArrayList<String>();
  		urls.add(url);
  		return createLayer(id, conf, urls);
  	}
docs: Create a new tile based layer with an URL to a tile service.
  <p/>
  The URL should have placeholders for the x- and y-coordinate and tile level in the form of {x}, {y}, {z}.
  The Y-coordinate can be inverted by specifying {-y} instead of {y}.
  The file extension of the tiles should be part of the URL.
  
  @param id   The unique ID of the layer.
  @param conf The tile configuration.
  @param url  The URL to the tile service.
  @return A new tile based layer.