code: public OsmLayer createDefaultOsmLayer(String id, int nrOfLevels) {
  		OsmLayer layer = new OsmLayer(id, createOsmTileConfiguration(nrOfLevels));
  		layer.addUrls(Arrays.asList(DEFAULT_OSM_URLS));
  		return layer;
  	}
docs: Create a new OSM layer with the given ID and tile configuration. The layer will be configured
  with the default OSM tile services so you don't have to specify these URLs yourself.
  
  @param id The unique ID of the layer.
  @param conf The tile configuration.
  @return A new OSM layer.
  @since 2.2.1