class_docstr: Class for importing CatBoost models.
class_docstr_tok: ["Class","for","importing","CatBoost","models","."]
docstr: Return the number of output classes.
  
  :return: Number of classes in the data.
docstr_tok: ["Return","the","number","of","output","classes",".",":","return",":","Number","of","classes","in","the","data","."]
code: def _get_nb_classes(self) -> int:
      """
      Return the number of output classes.
  
      :return: Number of classes in the data.
      """
      if self._model.classes_ is not None:
          return len(self._model.classes_)
  
      return -1
  
file_path: adversarial-robustness-toolbox/art/estimators/classification/catboost.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import logging
  import os
  import pickle
  from typing import List, Optional, Union, Tuple, TYPE_CHECKING
  import numpy
  from art.estimators.classification.classifier import ClassifierDecisionTree
  from art import config
label_desc: Use image node_id 6 for calling the CatBoostARTClassifier obj's underlying member method code with example usage: obj._get_nb_classes() and returns: unknown, len