anchor.diff:          _sessionManagerInstance != null) {
         _sessionManagerInstance.close();
         _sessionManagerInstance = null;
  -      _servers.remove(_serviceId);
       }
     }
   
  
positive.code:     _state = _CLOSING;
      _socket.destroy();
      _httpServer._connectionClosed(this);
      _connections.remove(_serviceId);
    }
  
    Future<Socket> detachSocket() {
  
negative.code:     _controller =
          new StreamController<HttpRequest>(sync: true, onCancel: close);
      idleTimeout = const Duration(seconds: 120);
    }
  
    _HttpServer.listenOn(this._serverSocket) : _closeServer = false {
      _controller =
          new StreamController<HttpRequest>(sync: true, onCancel: close);
      idleTimeout = const Duration(seconds: 120);
    }
  
    static HttpHeaders _initDefaultResponseHeaders() {
  