anchor.diff:      _mouseOut = _mouseOutHandler;
       _mouseMove = _mouseMoveHandler;
   
  -    // add mouse down handlers to the targets
  -    /*for(Element t in _targets) {
  -      _listen("mouseDown", t);
  -    }*/
  -
       // add initial element(s)
       // non-null check helps dart2js
       if(target != null) {
  
positive.code:   set enabled(bool e) {
      _logger.fine("setting enabled to $e");
      // if we are currently dragging, delay a disable until it ends
      // TODO yikes, this is kind of scary
      if(_dragging && _enabled && !e) {
        _delayedDisable = true;
        return;
  
negative.code:     _pendingToDrag();
  
      // send over event
      _dragOverStreamController.add(new DragOverEvent._(this, _currentTarget, event, event.currentTarget));
    }
    void _mouseOutHandler(MouseEvent event) {
      // only respond to this event when the element we're going to is
  