Return items (excluding top level items)

def get_items(self):
        """Return items (excluding top level items)"""
        itemlist = []
        def add_to_itemlist(item):
            for index in range(item.childCount()):
                citem = item.child(index)
                itemlist.append(citem)
                add_to_itemlist(citem)
        for tlitem in self.get_top_level_items():
            add_to_itemlist(tlitem)
        return itemlist