@property
    def manual_dir(self):
        return self._data_dir

    @property
    def downloaded_size(self):
        """Returns the total size of downloaded files."""
        return sum(checksums_dict["num_bytes"] for checksums_dict in self._recorded_sizes_checksums.values())

    def _record_sizes_checksums(self, url_or_urls: NestedDataStructure, downloaded_path_or_paths: NestedDataStructure):
        """Record size/checksum of downloaded files."""
        delay = 5
        for url, path in hf_tqdm(
            list(zip(url_or_urls.flatten(), downloaded_path_or_paths.flatten())),
            delay=delay,
            desc="Computing checksums",
        ):
            # call str to support PathLike objects
            self._recorded_sizes_checksums[str(url)] = get_size_checksum_dict(
                path, record_checksum=self.record_checksums
            )

    def download(self, url_or_urls):
        """Download given URL(s).