class ApiResponse { final T? data; final String? error; final int? statusCode; const ApiResponse({this.data, this.error, this.statusCode}); bool get isSuccess => error == null && data != null; factory ApiResponse.success(T data, {int? statusCode}) { return ApiResponse(data: data, statusCode: statusCode); } factory ApiResponse.failure(String error, {int? statusCode}) { return ApiResponse(error: error, statusCode: statusCode); } }