anchor.diff:  extension DomCSSStyleSheetExtension on DomCSSStyleSheet {
     external DomCSSRuleList get cssRules;
     int insertRule(String rule, [int? index]) => js_util
  -      .callMethod(this, 'insertRule', <Object>[rule, if (index != null) index]);
  +      .callMethod<double>(
  +          this, 'insertRule',
  +          <Object>[rule, if (index != null) index.toDouble()]).toInt();
   }
   
   @JS()
  
positive.code: 
  extension DomHistoryExtension on DomHistory {
    dynamic get state => js_util.dartify(js_util.getProperty(this, 'state'));
    external void go([int? delta]);
    void pushState(dynamic data, String title, String? url) =>
        js_util.callMethod(this, 'pushState', <Object?>[
          if (data is Map || data is Iterable) js_util.jsify(data as Object) else data,
  
negative.code:   external num get offsetY;
    DomPoint get client => DomPoint(clientX, clientY);
    DomPoint get offset => DomPoint(offsetX, offsetY);
    int get button =>
        js_util.getProperty<double>(this, 'button').toInt();
    int? get buttons =>
        js_util.getProperty<double?>(this, 'buttons')?.toInt();
    external bool getModifierState(String keyArg);
  }
  
  