code: def nodes_touching_tile(tile_id):
      
      coord = tile_id_to_coord(tile_id)
      nodes = []
      for offset in _tile_node_offsets.keys():
          nodes.append(coord + offset)
      # logging.debug('tile_id={}, nodes touching={}'.format(tile_id, nodes))
      return nodes
docs: Get a list of node coordinates touching the given tile.
  
      :param tile_id: tile identifier, Tile.tile_id
      :return: list of node coordinates touching the given tile, list(int)