code: def test_default(self, toy_df):
      gb = GroupBy(["color", "group"])
      res = Shift()(toy_df, gb, "x", {})
      for col in toy_df:
          assert_series_equal(toy_df[col], res[col])
  
imports: from itertools import product
  import numpy
  import pandas
  from pandas.testing import assert_series_equal
  from numpy.testing import assert_array_equal, assert_array_almost_equal
  from seaborn._core.moves import Dodge, Jitter, Shift, Stack, Norm
  from seaborn._core.rules import categorical_order
  from seaborn._core.groupby import GroupBy
  import pytest
label_desc: Use image node_id 1 for calling the TestShift obj's underlying member method code with example usage: obj.test_default(toy_df) without return types