code: def remove_duplicates(utterances: List[Utterance]) -> List[Utterance]:
      
  
      filtered_utters = []
      utter_set = set() # type: Set[Tuple[int, int, str]]
      for utter in utterances:
          if (utter.start_time, utter.end_time, utter.text) in utter_set:
              continue
          filtered_utters.append(utter)
          utter_set.add((utter.start_time, utter.end_time, utter.text))
  
      return filtered_utters
docs: Removes utterances with the same start_time, end_time and text. Other
      metadata isn't considered.