Get a list of edge coordinates touching the given tile.

    :param tile_id: tile identifier, Tile.tile_id
    :return: list of edge coordinates touching the given tile, list(int)

def edges_touching_tile(tile_id):
    """
    Get a list of edge coordinates touching the given tile.

    :param tile_id: tile identifier, Tile.tile_id
    :return: list of edge coordinates touching the given tile, list(int)
    """
    coord = tile_id_to_coord(tile_id)
    edges = []
    for offset in _tile_edge_offsets.keys():
        edges.append(coord + offset)
    # logging.debug('tile_id={}, edges touching={}'.format(tile_id, edges))
    return edges