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

        :param asset_receiver: the notification callback
        :type asset_receiver: ``osid.repository.AssetReceiver``
        :return: an ``AssetNotificationSession``
        :rtype: ``osid.repository.AssetNotificationSession``
        :raise: ``NullArgument`` -- ``asset_receiver`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_asset_notification()`` is ``false``

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