code: def test_expand_event_df_no_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=False,
      )
  
      pd.testing.assert_frame_equal(
          pd.concat(
              [event_labels.rename("A"), event_labels.rename("B")],
              axis=1,
          ),
          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 4 for calling a global function with example usage: test_expand_event_df_no_freq() without return types