code: def _get_node_split_feature(self, node_index: int) -> int:
      return self._tree.feature[node_index]
  
imports: from __future__ import annotations
  from functools import lru_cache
  import itertools
  from typing import List
  from typing import Set
  from typing import Tuple
  from typing import TYPE_CHECKING
  from typing import Union
  import numpy
label_desc: Use image node_id 17 for calling the _FanovaTree obj's underlying member method code with example usage: obj._get_node_split_feature(node_index) and returns: self