code: def test_add_t_start_end_to_utt_obj(
      alignment, expected_output_utterance, output_timestep_duration
  ):
      input_utterance = copy.deepcopy(expected_output_utterance)
  
      # set all t_start and t_end to None in input_utterance
      for segment_or_token in input_utterance.segments_and_tokens:
          if type(segment_or_token) is Segment:
              segment = segment_or_token
              segment.t_start = None
              segment.t_end = None
  
              for word_or_token in segment.words_and_tokens:
                  if type(word_or_token) is Word:
                      word = word_or_token
                      word.t_start = None
                      word.t_end = None
  
                      for token in word.tokens:
                          token.t_start = None
                          token.t_end = None
                  else:
                      token = word_or_token
                      token.t_start = None
                      token.t_end = None
  
          else:
              token = segment_or_token
              token.t_start = None
              token.t_end = None
  
      output_utterance = add_t_start_end_to_utt_obj(
          input_utterance, alignment, output_timestep_duration
      )
      assert output_utterance == expected_output_utterance
  
label_desc: Use image node_id 1 for calling a global function with example usage: test_add_t_start_end_to_utt_obj(alignment, expected_output_utterance, output_timestep_duration) without return types