anchor.diff:      });
     }
   
  -  void dispose() {
  -    _disposables.dispose();
  -  }
  -
  -  /// Installs the feature into [editor] if it responsible for a .dart file, noop if not.
  +  /// Installs the feature into [editor] if it responsible for a .dart file,
  +  /// noop if not.
     void _installInto(TextEditor editor) {
       if (!isDartFile(editor.getPath())) return;
   
       new TooltipManager(editor);
     }
  +
  +  void dispose() => _disposables.dispose();
   }
   
   /// Manages the display of tooltips for a single [TextEditor].
  
positive.code:   String _tooltipContent(HoverInformation hover) =>
        hover.elementDescription ?? hover.staticType ?? hover.propagatedType;
  
    void _disposeTooltip() {
      _tooltipElement?.dispose();
    }
  
    @override
    void dispose() {
      _disposeTooltip();
    }
  }
  
  /// Basic tooltip element with single [String] content capable of attaching itself to a [TextEditor]
  /// at a given position relative to its top,left corner.
  class TooltipElement extends CoreElement {
    static const int _offset = 12;
  
  
negative.code:   /// Returns true if the tooltip feature is enabled.
    bool get _isTooltipEnabled => atom.config.getValue('$pluginId.hoverTooltip');
  
    /// Returns the offset in the current buffer corresponding to the screen
    /// position of the [MouseEvent].
    int _offsetFromMouseEvent(html.MouseEvent e) {
      JsObject component = _editor.view['component'];
      Point bufferPt = component.callMethod('screenPositionForMouseEvent', [e]);
  