@Override
    public boolean equals(Object other) {
        //类型检查
        if (other == null || !(other instanceof MessageID)) {
            return false;
        }
        //必须都有id
        if (id == null || ((MessageID) other).id == null) {
            return false;
        }
        //id比较
        return bytesEqual(id, ((MessageID) other).id);

    }