code: def test_group_None(fill_df):
      """Raise ValueError if entry is None."""
      with pytest.raises(
          ValueError,
          match="label in the columns argument cannot be None.",
      ):
          fill_df.complete("group", "item_id", None)
  
imports: from string import ascii_lowercase
  import numpy
  import pandas
  import pytest
  from hypothesis import given, settings
  from pandas.testing import assert_frame_equal
  from janitor.testing_utils.strategies import categoricaldf_strategy
label_desc: Use image node_id 11 for calling a global function with example usage: test_group_None(fill_df) without return types