How to use the nhentai.utils.DB function in nhentai

pass
    except UnicodeDecodeError:
        exit(0)

    args, _ = parser.parse_args(sys.argv[1:])

    if args.html_viewer:
        generate_html()
        exit(0)

    if args.main_viewer and not args.id and not args.keyword and not args.favorites:
        generate_main_html()
        exit(0)

    if args.clean_download_history:
        with DB() as db:
            db.clean_all()

        logger.info('Download history cleaned.')
        exit(0)

    if os.path.exists(constant.NHENTAI_COOKIE):
        with open(constant.NHENTAI_COOKIE, 'r') as f:
            constant.COOKIE = f.read()

    if args.cookie:
        try:
            if not os.path.exists(constant.NHENTAI_HOME):
                os.mkdir(constant.NHENTAI_HOME)

            with open(constant.NHENTAI_COOKIE, 'w') as f:
                f.write(args.cookie)

if doujinshi_info:
                doujinshi_list.append(Doujinshi(name_format=options.name_format, **doujinshi_info))

            if (i + 1) % 10 == 0:
                logger.info('Progress: %d / %d' % (i + 1, len(doujinshi_ids)))

    if not options.is_show:
        downloader = Downloader(path=options.output_dir, size=options.threads,
                                timeout=options.timeout, delay=options.delay)

        for doujinshi in doujinshi_list:

            doujinshi.downloader = downloader
            doujinshi.download()
            if options.is_save_download_history:
                with DB() as db:
                    db.add_one(doujinshi.id)

            if not options.is_nohtml and not options.is_cbz:
                generate_html(options.output_dir, doujinshi)
            elif options.is_cbz:
                generate_cbz(options.output_dir, doujinshi, options.rm_origin_dir)

        if options.main_viewer:
            generate_main_html(options.output_dir)

        if not platform.system() == 'Windows':
            logger.log(15, '🍻 All done.')
        else:
            logger.log(15, 'All done.')

    else:

elif options.keyword:
        doujinshis = search_parser(options.keyword, sorting=options.sorting, page=options.page)

    elif not doujinshi_ids:
        doujinshi_ids = options.id

    if index:
        doujinshis = tag_parser(options.language, max_page=options.max_page, index=index)

    print_doujinshi(doujinshis)
    if options.is_download and doujinshis:
        doujinshi_ids = [i['id'] for i in doujinshis]

        if options.is_save_download_history:
            with DB() as db:
                data = set(db.get_all())

            doujinshi_ids = list(set(doujinshi_ids) - data)

    if doujinshi_ids:
        for i, id_ in enumerate(doujinshi_ids):
            if options.delay:
                time.sleep(options.delay)

            doujinshi_info = doujinshi_parser(id_)

            if doujinshi_info:
                doujinshi_list.append(Doujinshi(name_format=options.name_format, **doujinshi_info))

            if (i + 1) % 10 == 0:
                logger.info('Progress: %d / %d' % (i + 1, len(doujinshi_ids)))