Args:
            transform (`Callable`, *optional*):
                User-defined formatting transform, replaces the format defined by [`~datasets.Dataset.set_format`].
                A formatting function is a callable that takes a batch (as a dict) as input and returns a batch.
                This function is applied right before returning the objects in `__getitem__`.
            columns (`List[str]`, *optional*):
                Columns to format in the output.
                If specified, then the input batch of the transform only contains those columns.
            output_all_columns (`bool`, defaults to False):
                Keep un-formatted columns as well in the output (as python objects).
                If set to `True`, then the other un-formatted columns are kept with the output of the transform.

        Example: