anchor.diff:    }
   
     void setThemeColor(ui.Color color) {
  -    html.MetaElement? theme = html.document.querySelector('#flutterweb-theme') as html.MetaElement?;
  +    html.MetaElement? theme =
  +        html.document.querySelector('#flutterweb-theme') as html.MetaElement?;
       if (theme == null) {
         theme = html.MetaElement()
           ..id = 'flutterweb-theme'
  
positive.code:   }
  
    static void setElementTransform(html.Element element, String transformValue) {
      js_util.setProperty(js_util.getProperty(element, 'style'), 'transform',
          transformValue);
    }
  
    void setText(html.Element element, String text) {
  
negative.code:   static bool? _ellipseFeatureDetected;
  
    /// Draws CanvasElement ellipse with fallback.
    static void ellipse(
        html.CanvasRenderingContext2D context,
        double centerX,
        double centerY,
        double radiusX,
        double radiusY,
        double rotation,
        double startAngle,
        double endAngle,
        bool antiClockwise) {
      _ellipseFeatureDetected ??= js_util.getProperty(context, 'ellipse') != null;
      if (_ellipseFeatureDetected!) {
        context.ellipse(centerX, centerY, radiusX, radiusY, rotation, startAngle,
            endAngle, antiClockwise);
      } else {
        context.save();
        context.translate(centerX, centerY);
  