anchor.diff:    static Map<int, OverwriteElement> _objects = new Map<int, OverwriteElement>();
     // a stream controller for change events on the element
     StreamController _streamController;
  -  
  +
     // The element to implement overwrite mode in
     TextAreaElement _element;
     // An element used to calculate text width
     PreElement _widthEl;
  -  
  +
     StreamSubscription _focusSub;
     StreamSubscription _pasteSub;
     StreamSubscription _cutSub;
     StreamSubscription _downSub;
     StreamSubscription _pressSub;
  -  
  +
     // The current insert mode
     OverwriteMode _mode = OverwriteMode.OVERWRITE;
   
  
positive.code:       });
      };
    }
    
    // Create an overwrite object that implements overwrite mode on the input element 
    OverwriteElement(TextAreaElement this._element) {
      // create a stream controller for the element
      _streamController = new StreamController<OverwriteEvent>();
      
      // create element for determining text width
      _widthEl = new PreElement()
        // set style elements to make invisible
  
negative.code:       ..style.opacity = "0";
      // add element to body
      document.body.children.add(_widthEl);
  
      // On focus, update the width of the element to fill available space
      _focusSub = _element.onFocus.listen(_changeEventFunction((e) {
        // pad contents
  