code: def _change_no_children_value(self, children):
      return children.fillna(self.__class__.NO_CHILDREN)
  
imports: import json
  import math
  from collections import defaultdict
  from typing import List, Mapping
  import numpy
  from dtreeviz.models.shadow_decision_tree import VisualisationNotYetSupportedError
  from dtreeviz.models.shadow_decision_tree import ShadowDecTree
  from dtreeviz import utils
  import xgboost
  from xgboost.core import Booster
label_desc: Use image node_id 20 for calling the ShadowXGBDTree obj's underlying member method code with example usage: obj._change_no_children_value(children) and returns: children