public async Task <string> DownloadSiteAsStringAsync(string url)
        {
            var siteContent = _siteRepository.GetSiteContent(url);

            if (siteContent != null)
            {
                return(await Task.FromResult(siteContent));
            }

            siteContent = await _crawler.DownloadSiteAsStringAsync(url);

            _siteRepository.AddSiteContent(url, siteContent);

            return(siteContent);
        }