code: def test_truncate_datetime_dataframe_do_nothing():
      """Ensure nothing changes (and no errors raised) if there are no datetime-
      compatible columns.
      """
      in_data = {
          "a": [1, 0],
          "b": ["foo", ""],
          "c": [np.nan, 3.0],
          "d": [True, False],
      }
  
      result = pd.DataFrame(in_data).truncate_datetime_dataframe("year")
      expected = pd.DataFrame(in_data)
  
      assert_frame_equal(result, expected)
  
file_path: pyjanitor/tests/functions/test_truncate_datetime.py
imports: from datetime import datetime
  import numpy
  import pandas
  import pytest
  from pandas.testing import assert_frame_equal
label_desc: Use image node_id 3 for calling a global function with example usage: test_truncate_datetime_dataframe_do_nothing() without return types