How to use the nhentai.logger.logger.critical function in nhentai

title = doujinshi_info.find('h1').text
    subtitle = doujinshi_info.find('h2')

    doujinshi['name'] = title
    doujinshi['subtitle'] = subtitle.text if subtitle else ''

    doujinshi_cover = html.find('div', attrs={'id': 'cover'})
    img_id = re.search('/galleries/([\d]+)/cover\.(jpg|png|gif)$', doujinshi_cover.a.img.attrs['data-src'])

    ext = []
    for i in html.find_all('div', attrs={'class': 'thumb-container'}):
        _, ext_name = os.path.basename(i.img.attrs['data-src']).rsplit('.', 1)
        ext.append(ext_name)

    if not img_id:
        logger.critical('Tried yo get image id failed')
        exit(1)

    doujinshi['img_id'] = img_id.group(1)
    doujinshi['ext'] = ext

    pages = 0
    for _ in doujinshi_info.find_all('div', class_=''):
        pages = re.search('([\d]+) pages', _.text)
        if pages:
            pages = pages.group(1)
            break
    doujinshi['pages'] = int(pages)

    # gain information of the doujinshi
    information_fields = doujinshi_info.find_all('div', attrs={'class': 'field-name'})
    needed_fields = ['Characters', 'Artists', 'Languages', 'Tags', 'Parodies', 'Groups', 'Categories']

if args.favorites:
        if not constant.COOKIE:
            logger.warning('Cookie has not been set, please use `nhentai --cookie \'COOKIE\'` to set it.')
            exit(1)

    if args.id:
        _ = [i.strip() for i in args.id.split(',')]
        args.id = set(int(i) for i in _ if i.isdigit())

    if args.file:
        with open(args.file, 'r') as f:
            _ = [i.strip() for i in f.readlines()]
            args.id = set(int(i) for i in _ if i.isdigit())

    if (args.is_download or args.is_show) and not args.id and not args.keyword and not args.favorites:
        logger.critical('Doujinshi id(s) are required for downloading')
        parser.print_help()
        exit(1)

    if not args.keyword and not args.id and not  args.favorites:
        parser.print_help()
        exit(1)

    if args.threads <= 0:
        args.threads = 1

    elif args.threads > 15:
        logger.critical('Maximum number of used threads is 15')
        exit(1)

    return args

if not isinstance(id_, (int,)) and (isinstance(id_, (str,)) and not id_.isdigit()):
        raise Exception('Doujinshi id({0}) is not valid'.format(id_))

    id_ = int(id_)
    logger.log(15, 'Fetching information of doujinshi id {0}'.format(id_))
    doujinshi = dict()
    doujinshi['id'] = id_
    url = '{0}/{1}'.format(constant.DETAIL_URL, id_)
    i = 0
    while 5 > i:
        try:
            response = request('get', url).json()
        except Exception as e:
            i += 1
            if not i < 5:
                logger.critical(str(e))
                exit(1)
            continue
        break

    doujinshi['name'] = response['title']['english']
    doujinshi['subtitle'] = response['title']['japanese']
    doujinshi['img_id'] = response['media_id']
    doujinshi['ext'] = ''.join([i['t'] for i in response['images']['pages']])
    doujinshi['pages'] = len(response['images']['pages'])

    # gain information of the doujinshi
    needed_fields = ['character', 'artist', 'language', 'tag', 'parody', 'group', 'category']
    for tag in response['tags']:
        tag_type = tag['type']
        if tag_type in needed_fields:
            if tag_type == 'tag':

not args.tag and not args.artist and not args.character and \
            not args.parody and not args.group and not args.language and not args.favorites:
        logger.critical('Doujinshi id(s) are required for downloading')
        parser.print_help()
        exit(1)

    if not args.keyword and not args.id and not args.tag and not args.artist and \
            not args.character and not args.parody and not args.group and not args.language and not args.favorites:
        parser.print_help()
        exit(1)

    if args.threads <= 0:
        args.threads = 1

    elif args.threads > 15:
        logger.critical('Maximum number of used threads is 15')
        exit(1)

    return args

args.id = set(int(i) for i in _ if i.isdigit())

    if (args.is_download or args.is_show) and not args.id and not args.keyword and not args.favorites:
        logger.critical('Doujinshi id(s) are required for downloading')
        parser.print_help()
        exit(1)

    if not args.keyword and not args.id and not  args.favorites:
        parser.print_help()
        exit(1)

    if args.threads <= 0:
        args.threads = 1

    elif args.threads > 15:
        logger.critical('Maximum number of used threads is 15')
        exit(1)

    return args

def __api_suspended_search_parser(keyword, sorting, page):
    logger.debug('Searching doujinshis using keywords {0}'.format(keyword))
    result = []
    i = 0
    while i < 5:
        try:
            response = request('get', url=constant.SEARCH_URL, params={'query': keyword, 'page': page, 'sort': sorting}).json()
        except Exception as e:
            i += 1
            if not i < 5:
                logger.critical(str(e))
                logger.warn('If you are in China, please configure the proxy to fu*k GFW.')
                exit(1)
            continue
        break

    if 'result' not in response:
        raise Exception('No result in response')

    for row in response['result']:
        title = row['title']['english']
        title = title[:85] + '..' if len(title) > 85 else title
        result.append({'id': row['id'], 'title': title})

    if not result:
        logger.warn('No results for keywords {}'.format(keyword))

for chunk in response.iter_content(2048):
                        f.write(chunk)

        except (requests.HTTPError, requests.Timeout) as e:
            if retried < 3:
                logger.warning('Warning: {0}, retrying({1}) ...'.format(str(e), retried))
                return 0, self._download(url=url, folder=folder, filename=filename, retried=retried+1)
            else:
                return 0, None

        except NhentaiImageNotExistException as e:
            os.remove(os.path.join(folder, base_filename.zfill(3) + extension))
            return -1, url

        except Exception as e:
            logger.critical(str(e))
            return 0, None

        return 1, url

if len(self.ext) != self.pages:
                logger.warning('Page count and ext count do not equal')

            for i in range(1, min(self.pages, len(self.ext)) + 1):
                download_queue.append('%s/%d/%d.%s' % (IMAGE_URL, int(self.img_id), i, self.ext[i-1]))

            self.downloader.download(download_queue, self.filename)

            '''
            for i in range(len(self.ext)):
                download_queue.append('%s/%d/%d.%s' % (IMAGE_URL, int(self.img_id), i+1, EXT_MAP[self.ext[i]]))
            '''

        else:
            logger.critical('Downloader has not been loaded')

response = None
            with open(os.path.join(folder, base_filename.zfill(3) + extension), "wb") as f:
                i = 0
                while i < 10:
                    try:
                        response = request('get', url, stream=True, timeout=self.timeout)
                        if response.status_code != 200:
                            raise NhentaiImageNotExistException

                    except NhentaiImageNotExistException as e:
                        raise e

                    except Exception as e:
                        i += 1
                        if not i < 10:
                            logger.critical(str(e))
                            return 0, None
                        continue

                    break

                length = response.headers.get('content-length')
                if length is None:
                    f.write(response.content)
                else:
                    for chunk in response.iter_content(2048):
                        f.write(chunk)

        except (requests.HTTPError, requests.Timeout) as e:
            if retried < 3:
                logger.warning('Warning: {0}, retrying({1}) ...'.format(str(e), retried))
                return 0, self._download(url=url, folder=folder, filename=filename, retried=retried+1)