anchor.diff:    HttpServer _server;
     String _host;
     int _port;
  -  List<shelf.Middleware> _middleware = new List();
  +  List _middleware = new List();
     Container _container;
     Config _config;
     _ResponseMapper _responseMapper;
  
positive.code:     return pipeline.addHandler(_handle);
    }
  
    shelf.Middleware _conditionalMiddleware(shelf.Middleware middleware) {
      return (shelf.Handler innerHandler) {
        return (shelf.Request request) {
          if (_shouldUseMiddlewareForRequest(request, middleware))
            return middleware(innerHandler)(request);
          return innerHandler(request);
        };
      };
  
negative.code:   var _highPriorityMiddleware = 0;
  
    void addMiddleware(Object middleware, {bool highPriority: false}) {
      if (highPriority) return _middleware.insert(
          _highPriorityMiddleware++, middleware);
      _middleware.add(middleware);
    }
  
    shelf.Middleware _createMiddleware(Object middleware) {
  