What is the proper way to rebuild QTreeWidget hierachy

[Guest]

In my application I need to be able to rebuild QTreeWidget hierarchy. Conceptually, I need to remove all tree nodes following some number of top level nodes and then add their replacements. I am confused how I need to use existing APIs to do the removal in order to achieve what I need.

I started by coding something like
@for( QTreeWidgetItem * item = tree.topLevelItem(3); item != nullptr; item = tree.topLevelItem(3) )
tree.removeItemWidget(item);
@
but quickly discovered that this loop never terminates. Subsequently I replaced the code with
@for( QTreeWidgetItem * item = tree.takeTopLevelItem(3); item != nullptr; item = tree.takeTopLevelItem(3) )
delete item;
@
This seems to produce desired effects on the screen. Can someone confirm that (a) this is a way I am expected to do it and (b) I am expected to delete no longer needed QTreeWidgetItems myself.