i am trying to create a proxy model using a read-only model that will have all the item in the R/O model under a single tree parent node. What function do I need to overwrite to make this happened? Do I derived from QAbstractItemModel or QAbstractProxyModel?

Original model
* A
** x y
* B
* C
** x y

Proxy Model (what I want)
* Name-String
** A
*** x y
** B
** C
*** x y