code: def flag_dipthongs(self, syllables: List[str]) -> List[int]:
          
          long_positions = []
          for idx, syl in enumerate(syllables):
              for dipthong in self.constants.DIPTHONGS:
                  if dipthong in syllables[idx]:
                      if not string_utils.starts_with_qu(syllables[idx]):
                          long_positions.append(idx)
          return long_positions
docs: Return a list of syllables that contain a dipthong
  
          :param syllables:
          :return: