code: def __remove_append_items(self, whole=False):
          
          for node in self.climb(whole=whole):
              for key in sorted(node.data.keys()):
                  if key.endswith('+'):
                      del node.data[key]
docs: internal method, delete all append items (ends with +)
          :param whole: pass thru 'whole' param to climb
          :return: None