code: def is_fit(self):
      return getattr(self.tree_model, "tree_") is not None
  
imports: from collections import defaultdict
  from typing import List, Mapping
  import numpy
  from sklearn.utils import compute_class_weight
  from dtreeviz.models.shadow_decision_tree import ShadowDecTree
  from dtreeviz.utils import criterion_remapping
label_desc: Use image node_id 2 for calling the ShadowSKDTree obj's underlying member method code with example usage: obj.is_fit() and returns: unknown