SOLVED TreeView: How to insert dragobject as new item

Hello guys!
Is possible to insert new TreeView items using drag and drop as new root childs? When TreeView have no any element to insert BEFORE or AFTER.
I'm using AcceptDragObject but can't understand how to reproduce issue when obj is None like in this note.

If obj is None then dragobject should be inserted as a child of the root.

Solved. There is TREEVIEW_OUTSIDE_DROP option.