def METHOD_NAME(dataset: zarr.Array) -> pd.DataFrame:
    """Reads old format of dataframes"""
    # NOTE: Likely that categoricals need to be removed from uns
    warn(
        f"'{dataset.name}' was written with a very old version of AnnData. "
        "Consider rewriting it.",
        OldFormatWarning,
    )
    df = pd.DataFrame(_from_fixed_length_strings(dataset[()]))
    df.set_index(df.columns[0], inplace=True)
    return df