code: def _get_complexity(self, BaseEstimator, complexity_measure):
      return compute_tree_complexity(
          BaseEstimator.tree_, self.complexity_measure
      )
  
imports: from copy import deepcopy
  from typing import List
  import numpy
  from sklearn import datasets
  from sklearn.base import BaseEstimator
  from sklearn.model_selection import cross_val_score, train_test_split
  from sklearn.tree import DecisionTreeClassifier
  from imodels.tree.hierarchical_shrinkage import HSTreeRegressor, HSTreeClassifier
  from imodels.util.tree import compute_tree_complexity
label_desc: Use image node_id 4 for calling the DecisionTreeCCPRegressor obj's underlying member method code with example usage: obj._get_complexity(BaseEstimator, complexity_measure) and returns: compute_tree_complexity