def apply_preprocessing(self, x: np.ndarray, y: np.ndarray, fit: bool) -> tuple[Any, Any]:
        """
        Access function to get preprocessing

        :param x: unprocessed input data.
        :param y: unprocessed labels.
        :param fit: `True` if the function is call before fit/training and `False` if the function is called before a
                     predict operation.
        :return: Tuple with the processed input data and labels.
        """
        x_preprocessed, y_preprocessed = self._apply_preprocessing(x, y, fit=fit)
        return x_preprocessed, y_preprocessed

        Access function to get preprocessing

        :param x: unprocessed input data.
        :param y: unprocessed labels.
        :param fit: `True` if the function is call before fit/training and `False` if the function is called before a
                     predict operation.
        :return: Tuple with the processed input data and labels.
        
art/estimators/certification/interval/pytorch.py