Response<T>  constructor 
      
      Response<T> ({ 
    
    
- T? data,
- required RequestOptions requestOptions,
- int? statusCode,
- String? statusMessage,
- bool isRedirect = false,
- List<RedirectRecord> redirects = const [],
- Map<String, dynamic> ? extra,
- Headers? headers,
Implementation
Response({
  this.data,
  required this.requestOptions,
  this.statusCode,
  this.statusMessage,
  this.isRedirect = false,
  this.redirects = const [],
  Map<String, dynamic>? extra,
  Headers? headers,
})  : headers = headers ??
          Headers(preserveHeaderCase: requestOptions.preserveHeaderCase),
      extra = extra ?? <String, dynamic>{};