code: def get_items(self, maxlevel):
          
          itemlist = []
          def add_to_itemlist(item, maxlevel, level=1):
              level += 1
              for index in range(item.childCount()):
                  citem = item.child(index)
                  itemlist.append(citem)
                  if level <= maxlevel:
                      add_to_itemlist(citem, maxlevel, level)
          for tlitem in self.get_top_level_items():
              itemlist.append(tlitem)
              if maxlevel > 0:
                  add_to_itemlist(tlitem, maxlevel=maxlevel)
          return itemlist
docs: Return all items with a level <= `maxlevel`