docs: def is_descendant_of_gradebook(self, id_, gradebook_id):
          """Tests if an ``Id`` is a descendant of a gradebook.
  
          arg:    id (osid.id.Id): an ``Id``
          arg:    gradebook_id (osid.id.Id): the ``Id`` of a gradebook
          return: (boolean) - ``true`` if the ``id`` is a descendant of
                  the ``gradebook_id,`` ``false`` otherwise
          raise:  NotFound - ``gradebook_id`` is not found
          raise:  NullArgument - ``id`` or ``gradebook_id`` is ``null``
          raise:  OperationFailed - unable to complete request
          raise:  PermissionDenied - authorization failure
          *compliance: mandatory -- This method must be implemented.*
          *implementation notes*: If ``id`` is not found return ``false``.
  
          """
          # Implemented from template for
          # osid.resource.BinHierarchySession.is_descendant_of_bin
          if self._catalog_session is not None:
              return self._catalog_session.is_descendant_of_catalog(id_=id_, catalog_id=gradebook_id)
          return self._hierarchy_session.is_descendant(id_=id_, descendant_id=gradebook_id)