docs: def update_group(self, group_id, trigger):
          """
          Update an existing group trigger definition and its member definitions.
  
          :param group_id: Group trigger id to be updated
          :param trigger: Trigger object, the group trigger to be updated
          """
          data = self._serialize_object(trigger)
          self._put(self._service_url(['triggers', 'groups', group_id]), data, parse_json=False)