Using setDataSource method on a working DropDownTree, with same initial settings leads to not working clea button and not expanding a collapsed node. 

Dojo: https://dojo.telerik.com/uLUNudEJ 

Steps (clear button):

1. Open dojo and check that everything works correctly

2. Click reload button (calls setDataSource)

3. Clear all button does not work and cannot deselect the item from the tag's clear button.

Steps (expand):

1. Open dojo and open popup to see everything expands as expected

2. Click reload

3. Open popup

4. The last (initially collapsed) node cannot be expanded.