anchor.diff:        }
       }
   
  -    return new SyncHttpClientResponse._(
  +    return new SyncHttpClientResponse._(headers,
           reasonPhrase: reasonPhrase,
           statusCode: statusCode,
  -        body: body.toString(),
  -        headers: headers);
  -  }
  -
  -  SyncHttpClientResponse._(
  -      {this.reasonPhrase, this.statusCode, this.body, headers})
  +        body: body.toString());
  +  }
  +
  +  SyncHttpClientResponse._(Map<String, List<String>> headers,
  +      {this.reasonPhrase, this.statusCode, this.body})
         : this.headers = new _SyncHttpClientResponseHeaders(headers);
   }
   
  
positive.code: }
  
  class _SyncHttpClientRequestHeaders implements HttpHeaders {
    Map<String, List> _headers = <String, List<String>>{};
  
    final SyncHttpClientRequest _request;
    ContentType contentType;
  
negative.code:   HttpHeaders _headers;
  
    /// The headers associated with the HTTP request.
    HttpHeaders get headers =>
        _headers ??= new _SyncHttpClientRequestHeaders(this);
  
    /// The type of HTTP request being made.
    final String method;
  