code: def get_rhymelists(stanza, scheme):
      
      rhymelists = defaultdict(list)
      for rhyme_group, word_index in zip(scheme, stanza.word_indices):
          rhymelists[rhyme_group].append(word_index)
      return list(rhymelists.values())
docs: Returns ordered lists of the stanza's word indices as defined by given scheme