anchor.diff:    ///
     /// If null, the route is anonymous.
     final String name;
  -
  -  /// Whether this route is the very first route being pushed onto this [Navigator].
  -  ///
  -  /// The initial route typically skips any entrance transition to speed startup.
  -  ///
  -  /// This property has been deprecated. Uses [Navigator.onGenerateInitialRoutes]
  -  /// to customize initial routes instead. This feature was deprecated after
  -  /// v1.14.1.
  -  @Deprecated(
  -    'Uses onGenerateInitialRoutes to customize initial routes instead. '
  -    'This feature was deprecated after v1.14.1.'
  -  )
  -  final bool isInitialRoute;
   
     /// The arguments passed to this route.
     ///
  
positive.code:   /// Creates data used to construct routes.
    const RouteSettings({
      this.name,
      this.isInitialRoute = false,
      this.arguments,
    });
  
  
negative.code:     }());
      final RouteSettings settings = RouteSettings(
        name: name,
        arguments: arguments,
      );
      Route<T> route = widget.onGenerateRoute(settings) as Route<T>;
  