class UserFields { static const String id = "\$id"; static const String name = "name"; static const String email = "email"; static const String createdAt = "\$createdAt"; static const String updatedAt = "\$updatedAt"; static const String registrationDate = "registration"; } class User { String? id; String? name; String? email; User({ required this.id, required this.email, required this.name, }); User.fromJson(Map<String, dynamic> json) { id = json[UserFields.id]; name = json[UserFields.name]; email = json[UserFields.email]; } Map<String, dynamic> toJson() { final Map<String, dynamic> data = <String, dynamic>{}; data[UserFields.name] = name; return data; } }