code: def test_empty_directions(df):
      """Return dataframe if `directions` is empty."""
      assert_frame_equal(df.fill_direction(), df)
  
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 13 for calling a global function with example usage: test_empty_directions(df) without return types