anchor.diff:      return HttpServer.bind(host, port).then((httpServer) {
         var router = new Router("$presentedHost", {});
         var requestNavigator = new ZonedRequestNavigator(httpServer.asBroadcastStream(), router);
  -//      var safeNavigator = new SafeRequestNavigator(requestNavigator);
         return new Backend.config(httpServer, router, requestNavigator,
             () => new HMAC(hashMethod, UTF8.encode(key)), logFailedRequest(HttpBodyHandler.processRequest));
       });
  
positive.code:   ZonedRequestNavigator(_incoming, _router):super(_incoming, _router);
  
    dynamic _makeHandlerZoned(handler){
      zonedHandler(HttpRequest request, urlParams){
        Zone zone;
        runZoned((){
          zone = Zone.current;
          handler(request, urlParams);
        },
        zoneValues: {#requestBody: {'body': null}},
         onError: (e, s){
          logger.shout("Handling request failed. Reuest details:",
                        data: {"Headers": request.headers,
                               "Cookies": request.cookies,
                               "Address": request.connectionInfo.remoteAddress,
                               "Body": zone[#requestBody]['body']
                              }
                              , error: e, stackTrace: s);
        });
        }
      return zonedHandler;
    }
  
    void registerHandler(String routeName, dynamic handler){
  
negative.code:   Future prepareRequestHandler(HttpRequest httpRequest, Map urlParams,
      RequestHandler handler) {
      return _httpBodyExtractor(httpRequest).then((HttpBody body) {
        // remember requests body in zone for the purposes of logging in case of an error.
        // the make-it-safe 'if' statement is important for running tests.
        if (Zone.current[#requestBody] is Map && Zone.current[#requestBody].hasKey('body')){
          Zone.current[#requestBody]['body'] = body.body;
        }
  
        if (_defaulHttpHeaders != null) {
          _defaulHttpHeaders.forEach((header) =>
  