class BaseModel { bool? success; String? type; String? url; BaseModel({this.success, this.type, this.url}); factory BaseModel.fromJson(Map json) => BaseModel( success: json['success']?.toString().contains("true"), type: json['type']?.toString(), url: json['url']?.toString(), ); Map toJson() => { if (success != null) 'success': success, if (type != null) 'type': type, if (url != null) 'url': url, }; }