code: def update_list(self, picklist, list_id):
          
          route_values = {}
          if list_id is not None:
              route_values['listId'] = self._serialize.url('list_id', list_id, 'str')
          content = self._serialize.body(picklist, 'PickList')
          response = self._send(http_method='PUT',
                                location_id='01e15468-e27c-4e20-a974-bd957dcccebc',
                                version='5.0-preview.1',
                                route_values=route_values,
                                content=content)
          return self._deserialize('PickList', response)
docs: UpdateList.
          [Preview API] Updates a list.
          :param :class:`<PickList> <azure.devops.v5_0.work_item_tracking_process.models.PickList>` picklist:
          :param str list_id: The ID of the list
          :rtype: :class:`<PickList> <azure.devops.v5_0.work_item_tracking_process.models.PickList>`