code: def forum_list_filter(self, qs, user):
          
          # Any superuser should see all the forums
          if user.is_superuser:
              return qs
  
          # Check whether the forums can be viewed by the given user
          forums_to_hide = self._get_hidden_forum_ids(qs, user)
  
          return qs.exclude(id__in=forums_to_hide)
docs: Filters the given queryset in order to return a list of forums that can be seen and read
              by the specified user (at least).