docs: def _check_classifier(classifier):
          """
          Check if the classifier implements predict and predict_proba methods.
          """
          predict = getattr(classifier, "predict", None)
          if not callable(predict):
              raise ValueError('Classifier does not have predict method!')
  
          predict_proba = getattr(classifier, "predict_proba", None)
          if not callable(predict_proba):
              raise ValueError('Classifier does not have predict_proba method!')