def get_authorization_notification_session(self, authorization_receiver=None, proxy=None):
if proxy is None:<EOL><INDENT>raise NullArgument()<EOL><DEDENT>raise Unimplemented()<EOL>
Gets the notification session for notifications pertaining to authorization changes.

        arg:    authorization_receiver
                (osid.authorization.AuthorizationReceiver): the
                authorization receiver
        arg:    proxy (osid.proxy.Proxy): a proxy
        return: (osid.authorization.AuthorizationNotificationSession) -
                an ``AuthorizationNotificationSession``
        raise:  NullArgument - ``authorization_receiver`` is ``null``
        raise:  OperationFailed - unable to complete request
        raise:  Unimplemented -
                ``supports_authorization_notification()`` is ``false``
        *compliance: optional -- This method must be implemented if
        ``supports_authorization_notification()`` is ``true``.*