import 'package:json_annotation/json_annotation.dart'; part 'session.g.dart'; @JsonSerializable() class Session { final String url; final String apiKey; Session({required this.url, required this.apiKey}); Session.initial() : url = '', apiKey = ''; factory Session.fromJson(Map json) => _$SessionFromJson(json); Map toJson() => _$SessionToJson(this); }