SRNicoNico.Models.NicoNicoWrapper.NicoNicoRanking.GetRankingAsync C# (CSharp) Method

        public async Task<NicoNicoRankingEntry> GetRankingAsync(string category, int page) {

            try {

                var ret = new NicoNicoRankingEntry();

                ret.Period = Period;
                ret.Target = Target;

                var a = await NicoNicoWrapperMain.Session.GetAsync(string.Format(ApiUrl, category, page));

                var doc = new HtmlDocument();
                doc.LoadHtml2(a);

                ret.ItemList = new List<RankingItem>();

                var nodes = doc.DocumentNode.SelectNodes("//div[@class='contentBody video videoList01']/ul/li");
                if(nodes == null) {

                    return null;
                }

                foreach(var ranking in nodes) {

                    var item = new RankingItem();

                    item.Rank = ranking.SelectSingleNode("div[@class='rankingNumWrap']/p[@class='rankingNum']").InnerText;
                    item.RankingPoint = ranking.SelectSingleNode("div[@class='rankingNumWrap']/p[@class='rankingPt']").InnerText;

                    var wrap = ranking.SelectSingleNode("div[@class='videoList01Wrap']");

                    item.PostAt = wrap.SelectSingleNode("p[contains(@class, 'itemTime')]").InnerText;

                    item.Length = wrap.SelectSingleNode("div[@class='itemThumbBox']/span").InnerText;
                    item.ThumbNail = wrap.SelectSingleNode("div[@class='itemThumbBox']/div/a/img[2]").Attributes["data-original"].Value;

                    var content = ranking.SelectSingleNode("div[@class='itemContent']");

                    item.VideoUrl = "http://www.nicovideo.jp/" + content.SelectSingleNode("p/a").Attributes["href"].Value;
                    item.Title = content.SelectSingleNode("p/a").InnerText;

                    item.Description = content.SelectSingleNode("div[@class='wrap']/p[@class='itemDescription ranking']").InnerText;

                    var itemdata = content.SelectSingleNode("div[@class='itemData']/ul");

                    item.ViewCount = itemdata.SelectSingleNode("li[@class='count view']/span").InnerText;
                    item.CommentCount = itemdata.SelectSingleNode("li[@class='count comment']/span").InnerText;
                    item.MylistCount = itemdata.SelectSingleNode("li[@class='count mylist']/span").InnerText;

                    ret.ItemList.Add(item);
                }

                return ret;
            }catch(RequestTimeout) {

                return null;
            }
        }