anchor.diff:      });
   
       list.onDragOver.listen((MouseEvent ev){
  -      var target = ev.target;
  -      if(!list.children.contains(target) || !(target is LIElement)){
  +      var target = _getTargetFromEvent(ev);
  +      if(target == null){
           return;
         }
   
  
positive.code:     _setUp();
    }
  
    void _setUp(){
      list.queryAll("li").forEach((LIElement li){
        li.draggable = true;
  
negative.code:     });
  
      list.onDragEnd.listen((MouseEvent ev){
        var target = _getTargetFromEvent(ev);
        if(target == null){
          return;
        }
  
        LIElement li = target;
        _dragging_li = null;
        li.classes.remove("dragging");
  