code: def restore_expanded_state(self):
          
          if self.__expanded_state is None:
              return
          for item in self.get_items()+self.get_top_level_items():
              user_text = get_item_user_text(item)
              is_expanded = self.__expanded_state.get(hash(user_text))
              if is_expanded is not None:
                  item.setExpanded(is_expanded)
docs: Restore all items expanded state