code: def _get_node_children(self, node_index: int) -> Tuple[int, int]:
      return self._get_node_left_child(
          node_index
      ), self._get_node_right_child(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 14 for calling the _FanovaTree obj's underlying member method code with example usage: obj._get_node_children(node_index) and returns: self,  self