def METHOD_NAME(tmp_path_factory):
    # Create a temporary directory of dummy FITS files
    # from the header data. This directory is then used to
    # test directory patterns for database
    waveunit_dir = tmp_path_factory.mktemp('waveunit')
    header_files = [f for f in get_test_data_filenames()
                    if f.parents[0].relative_to(f.parents[1]).name == 'waveunit']
    for f in header_files:
        _ = write_image_file_from_header_file(f, waveunit_dir)
    return pathlib.Path(waveunit_dir)