Drag and Drop [preventDefault issue]

I'm using DragMouseController and DropMouseController to implement drag and drop on my project.

That works fine, the problem occurs when I drop an item out of the destination container, the object just "disappears".

I have thought of putting a drop handler at the level of the main form and somehow "cancel" the drop.

There is a "preventDefault" function, but it raises exception when I call it.
What am I doing wrong?

My code:
_DraggableItem.mxml_
```

```

_preventDefault on my MainContent.mxml:_
```
private function onDragEnd(event:DragEvent):void
{
event.preventDefault();
}

```

Reproduce the drag outside the destination using DraggableItem.mxml and MainContent.mxml, then read the DragMouseController and DropMouseController usage shown in the issue. Trace the dragDrop event and the preventDefault call, and confirm the behavior to consider the issue done: canceling the drop should not make the dragged object disappear or raise an exception.

Written by the indexing model from the issue text.