def is_descendant_of_objective(self, id=None, objective_id=None):
raise Unimplemented()<EOL>
Tests if an Id is a descendant of an objective.

        arg:    id (osid.id.Id): an Id
        arg:    objective_id (osid.id.Id): the Id of an objective
        return: (boolean) - true if the id is a descendant of the
                objective_id,  false otherwise
        raise:  NotFound - objective_id is not found
        raise:  NullArgument - id or objective_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.