Is there a recommended solution to recreate a tree node by node and have the same nodes expanded/collapsed?

 For example in the instance where you have a file explorer like app which has been generated programmatically based on an underlying customer data structure and would like to rebuild the tree but retain the expanded/collapsed nodes.  Almost as if you wanted to clone the tree and have it displayed exactly the same.

 I can imagine the brute force method of traversing the tree and keep a tally of all nodes that are expanded and reapply them.  This method doesn't really scale very well, but is that the only way?