updateByKValues method
通过用字符串key读取字段值的Map来更新字段
Implementation
@override
void updateByKValues(Map<String, dynamic> map) {
if (map.containsKey('_id')) _id = map['_id'];
if (map.containsKey('_bsid')) _bsid = map['_bsid'];
if (map.containsKey('_time')) _time = map['_time'];
if (map.containsKey('_extra')) _extra = map['_extra'];
if (map.containsKey('_trans')) _trans = map['_trans'];
if (map.containsKey('uid')) uid = map['uid'];
if (map.containsKey('rid')) rid = map['rid'];
}