@abc.abstractmethod<EOL><INDENT>def get_configuration_notification_session(self, configuration_receiver):<DEDENT>
return<EOL>
Gets the notification session for subscribing to changes to configurations.

        :param configuration_receiver: the notification callback
        :type configuration_receiver: ``osid.configuration.ConfigurationReceiver``
        :return: a ``ConfigurationNotificationSession``
        :rtype: ``osid.configuration.ConfigurationNotificationSession``
        :raise: ``NullArgument`` -- ``configuration_receiver`` is ``null``
        :raise: ``OperationFailed`` -- unable to complete request
        :raise: ``Unimplemented`` -- ``supports_configuration_notification()`` is ``false``

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