batch_size=batch_size,
                    keep_in_memory=keep_in_memory,
                    load_from_cache_file=load_from_cache_file,
                    cache_file_name=cache_file_names[k],
                    writer_batch_size=writer_batch_size,
                    fn_kwargs=fn_kwargs,
                    num_proc=num_proc,
                    desc=desc,
                )
                for k, dataset in self.items()
            }
        )