code: def test_fill_multiple_columns(df):
      """Fill on multiple columns with a single direction."""
      expected = df.copy()
      expected.loc[:, ["pet_type", "owner"]] = expected.loc[
          :, ["pet_type", "owner"]
      ].ffill()
      assert_frame_equal(
          df.fill_direction(**{"pet_type": "down", "owner": "down"}),
          expected,
      )
  
file_path: pyjanitor/tests/functions/test_fill_direction.py
imports: import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
  import janitor
label_desc: Use image node_id 6 for calling a global function with example usage: test_fill_multiple_columns(df) without return types