code: def user_slices(self, user_id=None):
          
          if not user_id:
              user_id = g.user.id
          Slice = models.Slice  # noqa
          FavStar = models.FavStar # noqa
          qry = (
              db.session.query(Slice,
                               FavStar.dttm).join(
                  models.FavStar,
                  sqla.and_(
                      models.FavStar.user_id == int(user_id),
                      models.FavStar.class_name == 'slice',
                      models.Slice.id == models.FavStar.obj_id,
                  ),
                  isouter=True).filter(
                  sqla.or_(
                      Slice.created_by_fk == user_id,
                      Slice.changed_by_fk == user_id,
                      FavStar.user_id == user_id,
                  ),
              )
              .order_by(Slice.slice_name.asc())
          )
          payload = [{
              'id': o.Slice.id,
              'title': o.Slice.slice_name,
              'url': o.Slice.slice_url,
              'data': o.Slice.form_data,
              'dttm': o.dttm if o.dttm else o.Slice.changed_on,
              'viz_type': o.Slice.viz_type,
          } for o in qry.all()]
          return json_success(
              json.dumps(payload, default=utils.json_int_dttm_ser))
docs: List of slices a user created, or faved