anchor.diff:        videoElement.srcObject = stream;
       }
       await videoElement.play();
  -    videoElement.mirror();
     }
   
     void stop() {
  
positive.code: }
  
  extension on html.VideoElement {
    void mirror() {
      style
        ..removeProperty('transform-origin')
        ..setProperty('width', '100%')
        ..setProperty('height', '100%')
        ..setProperty('transform', 'scaleX(-1)')
  
negative.code:       throw const CameraNotSupportedException();
      }
  
      videoElement = html.VideoElement()..applyDefaultStyles();
      divElement = html.DivElement()
        ..append(videoElement)
        ..style.setProperty('object-fit', 'cover');
  