anchor.diff:      if (core.hasBody) {
         if (core.hasBodyString) {
           _bodyStr = core.bodyStr();
  -        _body = _SimulatedResponseBody.string;
  +        _body = SimulatedResponseBodyType.string;
         } else if (core.hasBodyBytes) {
           _bodyBytes = core.bodyBytes();
  -        _body = _SimulatedResponseBody.bytes;
  +        _body = SimulatedResponseBodyType.bytes;
         } else {
           throw StateError('core has neither bytes or string body');
         }
       } else {
  -      _body = _SimulatedResponseBody.none;
  +      _body = SimulatedResponseBodyType.none;
       }
     }
   
  
positive.code: /// This class extends [Response] with methods to retrieve the body of the
  /// HTTP response. The other response classes (used by request handlers to
  /// produce HTTP responses) only allow the body to be produced.
  
  class SimulatedResponse extends Response {
    //================================================================
  
negative.code: 
    //================================================================
    // Methods
  
    //----------------------------------------------------------------
    /// The source format of the body.
    ///
    /// Indicates if there is a body, and (if there is) whether its source format
    /// was a String or a sequence of bytes.
  
    SimulatedResponseBodyType get bodyType => _body;
  
    //----------------------------------------------------------------
    /// Retrieves the body as a String.
  