code: def is_categorical_split(self, id) -> bool:
      node = self.tree_nodes[id]
      if "split_index" in node:
          if node["decision_type"] == "==":
              return True
      return False
  
imports: from collections import defaultdict
  from typing import List, Mapping
  import numpy
  import pandas
  from lightgbm.basic import Booster
  from dtreeviz.models.shadow_decision_tree import ShadowDecTree, VisualisationNotYetSupportedError
  from dtreeviz import utils
label_desc: Use image node_id 5 for calling the ShadowLightGBMTree obj's underlying member method code with example usage: obj.is_categorical_split(id) and returns: False, True