cloneExtra<E> method
克隆一个实例并赋值extra字段
Implementation
EasyPacket<E> cloneExtra<E>(E? extra) => EasyPacket<E>._(route: route, id: id, code: code, desc: desc, data: data, ucid: ucid, word: word, sign: sign, extra: extra);
克隆一个实例并赋值extra字段
EasyPacket<E> cloneExtra<E>(E? extra) => EasyPacket<E>._(route: route, id: id, code: code, desc: desc, data: data, ucid: ucid, word: word, sign: sign, extra: extra);