code: def _split_column_value(self, column_name):
      def split_value(value):
          if isinstance(value, str):
              return value.split("-")[1]
          else:
              return value
  
      return self.tree_to_dataframe.apply(
          lambda row: split_value(row.get(f"{column_name}")), axis=1
      )
  
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 19 for calling the ShadowXGBDTree obj's underlying member method code with example usage: obj._split_column_value(column_name) and returns: self, value, value