anchor.diff:    }
   
     /**
  -   * Toggles visibility of the outline
  +   * Toggles visibility of the outline.  Returns true if showing.
      */
  -  void toggle() {
  -    if (_outlineDiv.style.display == 'none') {
  -      _outlineDiv.style.display = 'block';
  +  bool _toggle() {
  +    if (_outlineContainer.style.display == 'none') {
  +      _outlineContainer.style.display = 'block';
  +      return true;
       } else {
  -      _outlineDiv.style.display = 'none';
  +      _outlineContainer.style.display = 'none';
  +      return false;
       }
     }
   
  
positive.code: class Outline {
    html.DivElement _outlineDiv;
    html.UListElement _rootList;
    services.AnalyzerService analyzer;
  
    List<OutlineTopLevelItem> children = [];
  
negative.code: 
      _outlineDiv.style
          ..position = 'absolute'
          ..minWidth = '40px'
          ..right = '10px'
          ..top ='10px'
          ..bottom = '10px'
          ..background = 'rgb(100, 100, 100)'
          ..borderRadius = '2px'
          ..zIndex = '100'
          ..opacity = '0.6'
          ..overflow = 'scroll';
  
      _outlineContainer = new html.DivElement();
      _outlineContainer.style
          ..height = '100%'
          ..width = '200px'
          ..overflow = 'scroll';
      _outlineDiv.append(_outlineContainer);
  
      html.ButtonElement toggleButton = new html.ButtonElement();
      toggleButton
          ..onClick.listen((e) => e.target.text = _toggle() ? ">" : "<")
          ..text = ">";
  
      toggleButton.style
          ..position = 'absolute'
          ..height ='20px'
          ..top ='50%'
          ..bottom ='50%';
  
      _outlineDiv.append(toggleButton);
    }
  
    /**
  