def get_grade_system_notification_session_for_gradebook(self, grade_system_receiver=None, gradebook_id=None):
if grade_system_receiver is None:<EOL><INDENT>raise NullArgument<EOL><DEDENT>if gradebook_id is None:<EOL><INDENT>raise NullArgument<EOL><DEDENT>raise Unimplemented()<EOL>
Gets the ``OsidSession`` associated with the grade system notification service for the given gradebook.

        arg:    grade_system_receiver
                (osid.grading.GradeSystemReceiver): the grade system
                receiver
        arg:    gradebook_id (osid.id.Id): the ``Id`` of the gradebook
        return: (osid.grading.GradeSystemNotificationSession) - ``a
                _grade_system_notification_session``
        raise:  NotFound - ``gradebook_id`` not found
        raise:  NullArgument - ``grade_system_receiver`` or
                ``gradebook_id`` is ``null``
        raise:  OperationFailed - ``unable to complete request``
        raise:  Unimplemented - ``supports_grade_system_notification()``
                or ``supports_visible_federation()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_grade_system_notification()`` and
        ``supports_visible_federation()`` are ``true``.*