attachment property Null safety
@JsonKey(fromJson: QChatSystemNotificationAttachment._fromJson, toJson: QChatSystemNotificationAttachment._toJson), read / write
通知附件字符串解析后的结构
Implementation
@JsonKey(
fromJson: QChatSystemNotificationAttachment._fromJson,
toJson: QChatSystemNotificationAttachment._toJson)
QChatSystemNotificationAttachment? attachment;