@abc.abstractmethod<EOL><INDENT>def get_assessment_notification_session(self, assessment_receiver, proxy):<DEDENT>
return<EOL>
Gets the notification session for notifications pertaining to assessment changes.

        :param assessment_receiver: the assessment receiver interface
        :type assessment_receiver: ``osid.assessment.AssessmentReceiver``
        :param proxy: a proxy
        :type proxy: ``osid.proxy.Proxy``
        :return: an ``AssessmentNotificationSession``
        :rtype: ``osid.assessment.AssessmentNotificationSession``
        :raise: ``NullArgument`` -- ``assessment_receiver`` or ``proxy`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_assessment_notification()`` is ``false``

        *compliance: optional -- This method must be implemented if
        ``supports_assessment_notification()`` is ``true``.*