code: def _get_comments_to_export(self, last_export_id=None):
          
          qs = comments.get_model().objects.order_by('pk')\
                  .filter(is_public=True, is_removed=False)
          if last_export_id is not None:
              print("Resuming after comment %s" % str(last_export_id))
              qs = qs.filter(id__gt=last_export_id)
          return qs
docs: Return comments which should be exported.