def __init__(
        self,
        classifier: "CLASSIFIER_NEURALNETWORK_TYPE",
        delta: float | None = None,
        layer: int | None = None,
        batch_size: int = 32,
    ):
        """
        Create a :class:`.FeatureAdversaries` instance.

        :param classifier: A trained classifier.
        :param delta: The maximum deviation between source and guide images.
        :param layer: Index of the representation layer.
        :param batch_size: Batch size.
        """
        super().__init__(estimator=classifier)

        self.delta = delta
        self.layer = layer
        self.batch_size = batch_size
        self._check_params()

        Create a :class:`.FeatureAdversaries` instance.

        :param classifier: A trained classifier.
        :param delta: The maximum deviation between source and guide images.
        :param layer: Index of the representation layer.
        :param batch_size: Batch size.
        
art/attacks/evasion/feature_adversaries/feature_adversaries_numpy.py