class Citizenship { Citizenship({ required this.country, required this.naturalBorn, }); final Country? country; final bool? naturalBorn; factory Citizenship.fromJson(Map json) => Citizenship( country: Country.fromJson(json["country"]), naturalBorn: json["natural_born"], ); Map toJson() => { "country": country!.toJson(), "natural_born": naturalBorn, }; } class Country { Country({ required this.id, required this.code, required this.name, }); final int? id; final String? code; final String? name; factory Country.fromJson(Map json) => Country( id: json["id"], code: json["code"], name: json["name"], ); Map toJson() => { "id": id, "code": code, "name": name, }; }