class TimeZone { final String name; final String offset; final String id; TimeZone({ required this.name, required this.offset, required this.id, }); factory TimeZone.fromJson(Map json) { return TimeZone( name: json['cityName'], offset: json['timeZoneOffset'], id: json['uuid'].toString(), // Ensure id is a String ); } Map toJson() { return { 'name': name, 'offset': offset, 'id': id, }; } }