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

        arg:    grade_entry_receiver (osid.grading.GradeEntryReceiver):
                the grade entry receiver
        arg:    gradebook_id (osid.id.Id): the ``Id`` of the gradebook
        arg:    proxy (osid.proxy.Proxy): a proxy
        return: (osid.grading.GradeEntryNotificationSession) - ``a
                _grade_entry_notification_session``
        raise:  NotFound - ``gradebook_id`` not found
        raise:  NullArgument - ``grade_entry_receiver, gradebook_id`` or
                ``porxy`` is ``null``
        raise:  OperationFailed - ``unable to complete request``
        raise:  Unimplemented - ``supports_grade_entry_notification()``
                or ``supports_visible_federation()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_grade_entry_notification()`` and
        ``supports_visible_federation()`` are ``true``.*