code: def _check_is_fitted(self):
      if not self.is_fitted:
          raise ValueError("Call .fit() before describing rules")
  
imports: from dataclasses import asdict, dataclass
  from typing import Dict, List, Optional, Union
  import numpy
  import pandas
  from sklearn.base import BaseEstimator
  from sklearn.ensemble import RandomForestClassifier
  from sklearn.model_selection import GridSearchCV, cross_val_predict
  from dowhy.causal_refuters.overrule.ruleset import BCSRulesetEstimator
  from dowhy.causal_refuters.overrule.utils import fatom
label_desc: Use image node_id 12 for calling the OverruleAnalyzer obj's underlying member method code with example usage: obj._check_is_fitted() without return types