import 'package:json_annotation/json_annotation.dart'; part 'rfid_model.g.dart'; @JsonSerializable() class RfidModel{ String uid; int count; RfidModel({ required this.uid, this.count = 0, }); factory RfidModel.fromJson(Map json) => _$RfidModelFromJson(json); Map toJson() => _$RfidModelToJson(this); }