code: def test_column_None(fill_df):
      """Test output if *columns is empty."""
      assert_frame_equal(fill_df.complete(), fill_df)
  
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 5 for calling a global function with example usage: test_column_None(fill_df) without return types