def METHOD_NAME(self):
    # empty
    g = GroupCoordinates([])
    repr(g)
    # nonempty
    c1 = Coordinates([[0, 1], [0, 1]], dims=["lat", "lon"])
    c2 = Coordinates([[[10, 11], [10, 11]]], dims=["lat_lon"])
    g = GroupCoordinates([c1, c2])
    repr(g)