ckages in this
        transaction.

        :param proxy: The URL of the proxy server, e.g. "http://proxy:8080"
        :param reply_handler: Callback function. If specified in combination
            with error_handler the method will be called asynchrounsouly.
        :param error_handler: Errback function. In case of an error the given
            callback gets the corresponding exception instance.
        :param defer: Run the method asynchrounsly and return a defer.Deferred.
            This options is only available as a keyword.

        :raises: aptdaemon.errors.NotAuthorizedError, dbus.DBusException
            aptdaemon.errors.ForeignTransaction,
        c