@abc.abstractmethod<EOL><INDENT>def get_composition_notification_session(self, composition_receiver):<DEDENT>
return<EOL>
Gets the notification session for notifications pertaining to composition changes.

        :param composition_receiver: the notification callback
        :type composition_receiver: ``osid.repository.CompositionReceiver``
        :return: a ``CompositionNotificationSession``
        :rtype: ``osid.repository.CompositionNotificationSession``
        :raise: ``NullArgument`` -- ``composition_receiver`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_composition_notification()`` is ``false``

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