code: def test_expand_event_df_freq():
      expanded_events = expand_events(
          pd.concat(
              [event_labels.rename("A"), event_labels.rename("B")],
              axis=1,
          ),
          left_expand="1hour",
          right_expand="1hour",
          freq_as_period=True,
      )
      true_expanded_events = pd.Series(
          [0, 1, 1, 1, 1, 1, 1, 1, nan, 0, 1, 1],
          index=pd.date_range(start="2017-1-1", periods=12, freq="D"),
      )
      true_expanded_events = pd.concat(
          [
              true_expanded_events.rename("A"),
              true_expanded_events.rename("B"),
          ],
          axis=1,
      )
      pd.testing.assert_frame_equal(
          true_expanded_events, expanded_events, check_dtype=False
      )
  
file_path: adtk/tests/test_expand_events.py
imports: import pandas
  from adtk.data import expand_events
label_desc: Use image node_id 3 for calling a global function with example usage: test_expand_event_df_freq() without return types