anchor.diff:      };
     }
   
  -  return runAppEngineRaw((HttpRequest request) {
  +  return appengine_internal.runAppEngine((HttpRequest request) {
       runZoned(() {
         handler(request);
       }, zoneValues: <Symbol, Object>{
  -      _APPENGINE_CONTEXT: contextFromRequest(request),
  +      _APPENGINE_CONTEXT: appengine_internal.contextFromRequest(request),
       }, onError: (error, stack) {
         errorHandler('Uncaught error in request handler zone: $error', stack);
   
  
positive.code:       try {
          request.response.statusCode = HttpStatus.INTERNAL_SERVER_ERROR;
        } on StateError catch (_) {}
        request.response.close().catchError((_) {
          errorHandler('Forcefully closing response, due to error in request '
                       'handler zone, resulted in an error: $error', stack);
        });
      });
    });
  
negative.code: 
  const Symbol _APPENGINE_CONTEXT = #appengine_context;
  
  /**
   * Starts serving requests coming to this AppEngine application.
   *
   * This function will start an HTTP server and will forward new HTTP requests
   * to [handler].
   *
   * The [handler] will be executed inside a new request handler zone for every
   * new request. This will isolate different requests from each other.
   * Each [handler] has access to a [ClientContext] using the [context] getter
   * in this library. It can be used to access appengine services, e.g. memcache.
   *
   * In case an uncaught error occurs inside the request handler, the request
   * will be closed with an "500 Internal Server Error", if possible, and the
   * given [onError] handler will be called.
   *
   * The [onError] function can take either the error object, or the error object
   * and a stack as an argument. If [onError] was not provided, errors will get
   * printed out to the stdout of this process.
   */
  Future runAppEngine(AppEngineRequestHandler handler, {Function onError}) {
    var errorHandler;
    if (onError != null) {
  