TreeList - How to drag and drop nodes between two treelists

This example demonstrates how to drag and drop nodes between two treelists. To do so, each extension has its client-side StartDragNode and EndDragNode events handled to:

- Add new drop targets for the node being dragged;
- Perform a callback to the server to update the state of both treelists.

This logic is implemented inside the MyDragHelper.js file.