code: public void loadTileSets (File file, Map<String, TileSet> tilesets)
          throws IOException
      {
          // load up the tilesets
          loadTileSets(new FileInputStream(file), tilesets);
      }
docs: Loads all of the tilesets specified in the supplied XML tileset
  description file and places them into the supplied map indexed
  by tileset name. This method is not reentrant, so don't go calling
  it from multiple threads.
  
  @param file the file in which the tileset definition file can be
  found.
  @param tilesets the map into which the tilesets will be placed,
  indexed by tileset name.