@Override
	public synchronized void dragOver(DropTargetDragEvent dtde) {
		updateAutoscroll(dtde.getLocation());

		if (activeDropTarget == null) {
			DropTargetDragEventWrapper eventWrapper = new DropTargetDragEventWrapper(dtde);
			primaryDropTarget.dragOver(eventWrapper);
			activeDropTarget = primaryDropTarget;
			if (!eventWrapper.isAccepted()) {
				activeDropTarget = secondaryDropTarget;
				secondaryDropTarget.dragOver(eventWrapper);
			}
			if (!eventWrapper.isAccepted()) {
				activeDropTarget = null;
			}
			eventWrapper.flush();
		} else 		{
			activeDropTarget.dragOver(dtde);
		}
	}
Combines two drop targets and sends events to them in priority order.  If the first drop target
accepts the event, then the second drop target is not accessed. 
<p>
Either of the given drop targets can be an instance of CascadedDropTarget, effectively creating 
a tree structure of drop targets.
Ghidra/Framework/Generic/src/main/java/ghidra/util/CascadedDropTarget.java