def __init__(self, estimator, attack_feature: int | slice = 0):
        """
        :param estimator: A trained estimator targeted for inference attack.
        :type estimator: :class:`.art.estimators.estimator.BaseEstimator`
        :param attack_feature: The index of the feature to be attacked.
        """
        super().__init__(estimator)
        self._check_attack_feature(attack_feature)
        self.attack_feature = get_feature_index(attack_feature)

        :param estimator: A trained estimator targeted for inference attack.
        :type estimator: :class:`.art.estimators.estimator.BaseEstimator`
        :param attack_feature: The index of the feature to be attacked.
        
art/attacks/attack.py