def forward(
        self, x: np.ndarray, column_pos: int | None = None, row_pos: int | None = None
    ) -> np.ndarray | "torch.Tensor":
        """
        Ablate batch of data at locations specified by column_pos and row_pos

        :param x: input image.
        :param column_pos: column position to specify where to retain the image
        :param row_pos: row position to specify where to retain the image. Not used for ablation type "column".
        """
        raise NotImplementedError

        Ablate batch of data at locations specified by column_pos and row_pos

        :param x: input image.
        :param column_pos: column position to specify where to retain the image
        :param row_pos: row position to specify where to retain the image. Not used for ablation type "column".
        
art/estimators/certification/derandomized_smoothing/ablators/ablate.py