code: def _get_nodes_values(self, column_name):
      nodes = self._get_column_value(self.NODE_COLUMN)
      nodes_values = self._get_column_value(column_name)
  
      return dict(zip(nodes, nodes_values))
  
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 18 for calling the ShadowXGBDTree obj's underlying member method code with example usage: obj._get_nodes_values(column_name) and returns: dict