Traverses root with the given path, creating missing members and elements as required, and applies update to the final value.
Note: if update returns undefined, the leaf node is deleted and any generated parents are discarded
Returns
the original (but modified) root, or the result of updating the original root if path is empty
Traverses root with the given path, creating missing members and elements as required, and applies update to the final value. Note: if update returns undefined, the leaf node is deleted and any generated parents are discarded
Returns
the original (but modified) root, or the result of updating the original root if path is empty