import 'package:json_annotation/json_annotation.dart'; part 'session_id.g.dart'; @JsonSerializable(explicitToJson: true) class SessionID { final String clientId; final String deviceId; const SessionID({ required this.clientId, required this.deviceId, }); factory SessionID.fromJson(Map json) => _$SessionIDFromJson(json); Map toJson() => _$SessionIDToJson(this); }