docs: def check_for_duplicate_comment(self, new):
          """
          Check that a submitted comment isn't a duplicate. This might be caused
          by someone posting a comment twice. If it is a dup, silently return the *previous* comment.
          """
          possible_duplicates = self.get_comment_model()._default_manager.using(
              self.target_object._state.db
          ).filter(
              content_type=new.content_type,
              object_pk=new.object_pk
          )
          for old in possible_duplicates:
              if old.post_date.date() == new.post_date.date() and old.text == new.text:
                  return old
  
          return new