code: def save_dash(self, dashboard_id):
          
          session = db.session()
          dash = (session
                  .query(models.Dashboard)
                  .filter_by(id=dashboard_id).first())
          check_ownership(dash, raise_if_false=True)
          data = json.loads(request.form.get('data'))
          self._set_dash_metadata(dash, data)
          session.merge(dash)
          session.commit()
          session.close()
          return json_success(json.dumps({'status': 'SUCCESS'}))
docs: Save a dashboard's metadata