code: def update_query(self, query_update, project, query, undelete_descendants=None):
          
          route_values = {}
          if project is not None:
              route_values['project'] = self._serialize.url('project', project, 'str')
          if query is not None:
              route_values['query'] = self._serialize.url('query', query, 'str')
          query_parameters = {}
          if undelete_descendants is not None:
              query_parameters['$undeleteDescendants'] = self._serialize.query('undelete_descendants', undelete_descendants, 'bool')
          content = self._serialize.body(query_update, 'QueryHierarchyItem')
          response = self._send(http_method='PATCH',
                                location_id='a67d190c-c41f-424b-814d-0e906f659301',
                                version='5.1-preview.2',
                                route_values=route_values,
                                query_parameters=query_parameters,
                                content=content)
          return self._deserialize('QueryHierarchyItem', response)
docs: UpdateQuery.
          [Preview API] Update a query or a folder. This allows you to update, rename and move queries and folders.
          :param :class:`<QueryHierarchyItem> <azure.devops.v5_1.work_item_tracking.models.QueryHierarchyItem>` query_update: The query to update.
          :param str project: Project ID or project name
          :param str query: The ID or path for the query to update.
          :param bool undelete_descendants: Undelete the children of this folder. It is important to note that this will not bring back the permission changes that were previously applied to the descendants.
          :rtype: :class:`<QueryHierarchyItem> <azure.devops.v5_1.work-item-tracking.models.QueryHierarchyItem>`