import 'package:json_annotation/json_annotation.dart'; part 'message_data.g.dart'; @JsonSerializable() class MessageData { @JsonKey(name: "lat") final double? latitude; @JsonKey(name: "lng") final double? longitude; @JsonKey(name: "speed") final double? speed; @JsonKey(name: "bearing") final double? bearing; @JsonKey(name: "addr") final String? address; @JsonKey(name: "network") final String? network; MessageData({this.latitude, this.longitude, this.speed, this.bearing, this.address, this.network}); factory MessageData.fromJson(Map json) => _$MessageDataFromJson(json); Map toJson() => _$MessageDataToJson(this); }