anchor.diff:  }
   
   class _Response {
  -  final Request _request;
  -  OutputStream _outputStream;
  -  String _reasonPhrase;
  +  final _request;
  +  final _outputStream;
  +  var _reasonPhrase;
     _Headers _headers;
  -  _Response(this._request) {
  -    _outputStream = new _ResponseOutputStream(_request);
  -    _reasonPhrase = null;
  -  }
  +  _Response(request) : _request = request, _outputStream = new _ResponseOutputStream(request);
   
     get outputStream() => _outputStream;
     get headers() {
  
positive.code: }
  
  class _Headers extends HeadersNative implements HttpHeaders {
    final _Request _request;
    _Headers(this._request);
  
    List<String> operator [](String name) {
  
negative.code: }
  
  class _ResponseOutputStream implements OutputStream {
    final _request;
    _ResponseOutputStream(this._request);
  
    bool writeString(String string, [Encoding encoding = Encoding.UTF_8]) {
  