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

        :param assessment_taken_receiver: the assessment taken receiver interface
        :type assessment_taken_receiver: ``osid.assessment.AssessmentTakenReceiver``
        :return: an ``AssessmentTakenNotificationSession``
        :rtype: ``osid.assessment.AssessmentTakenNotificationSession``
        :raise: ``NullArgument`` -- ``assessment_taken_receiver`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_assessment_taken_notification()`` is ``false``

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