def get_transform_type(tile_id):
    """
    Get the transform type specified in the tile id.
    Parameters
    ----------
    cooler_tile_id: str
        A tile id for a 2D tile (cooler)
    Returns
    -------
    transform_type: str
        The transform type requested for this tile
    """
    tile_id_parts = tile_id.split('.')
    if len(tile_id_parts) > 4:
        transform_method = tile_id_parts[4]
    else:
        transform_method = 'default'
    return transform_method
