code: def group_comments_by_round(comments, ranking=0):
      
      comment_rounds = {}
      ordered_comment_round_names = []
      for comment in comments:
          comment_round_name = ranking and comment[11] or comment[7]
          if comment_round_name not in comment_rounds:
              comment_rounds[comment_round_name] = []
              ordered_comment_round_names.append(comment_round_name)
          comment_rounds[comment_round_name].append(comment)
      return [(comment_round_name, comment_rounds[comment_round_name])
              for comment_round_name in ordered_comment_round_names]
docs: Group comments by the round to which they belong