public object ExtractProperties(CrawlResult crawlResult, IHtmlCollection <IElement> elements)
        {
            Directory.CreateDirectory(@"c:\temp\WebScraper");

            using (var client = new HttpClient())
            {
                foreach (var img in elements.SelectMany(e => e.QuerySelectorAll("img")))
                {
                    var src = new Uri(crawlResult.RequestUrl, new Uri(img.Attributes["src"].Value, UriKind.RelativeOrAbsolute));

                    var fileName = Path.Combine(@"c:\temp\WebScraper", Path.GetFileName(src.LocalPath));

                    if (File.Exists(fileName) == false)
                    {
                        Console.WriteLine($"Downloading {src} to {fileName}");

                        using (var f = File.OpenWrite(fileName))
                            using (var s = client.GetStreamAsync(src).Result)
                            {
                                s.CopyTo(f);
                            }
                    }
                    else
                    {
                        Console.WriteLine($"Skipping download of {src} to {fileName}");
                    }

                    img.SetAttribute("data-local-src", fileName);
                }
            }

            return(elements.Select(this.htmlSelector).Aggregate((prod, next) => prod + "\n" + next));
        }
 public static IEnumerable <IElement> QuerySelectorAll(this IHtmlCollection <IElement> source, string selector)
 {
     return(source.SelectMany(x => x.QuerySelectorAll(selector)));
 }