def get_bar_config(self, bar_id=None):
        """
        Get the configuration of a single bar. Defaults to the first if none is
        specified. Use :meth:`get_bar_config_list` to obtain a list of valid
        IDs.

        :rtype: BarConfigReply
        """
        if not bar_id:
            bar_config_list = self.get_bar_config_list()
            if not bar_config_list:
                return None
            bar_id = bar_config_list[0]

        data = self.message(MessageType.GET_BAR_CONFIG, bar_id)
        return json.loads(data, object_hook=BarConfigReply)
Get the configuration of a single bar. Defaults to the first if none is
        specified. Use :meth:`get_bar_config_list` to obtain a list of valid
        IDs.

        :rtype: BarConfigReply