OpenTween.TweenMain.FavAddAsyncInternal C# (CSharp) Method

        private async Task FavAddAsyncInternal(IProgress<string> p, CancellationToken ct, long statusId, TabModel tab)
        {
            if (ct.IsCancellationRequested)
                return;

            if (!CheckAccountValid())
                throw new WebApiException("Auth error. Check your account");

            PostClass post;
            if (!tab.Posts.TryGetValue(statusId, out post))
                return;

            if (post.IsFav)
                return;

            await Task.Run(async () =>
            {
                p.Report(string.Format(Properties.Resources.GetTimelineWorker_RunWorkerCompletedText15, 0, 1, 0));

                try
                {
                    await this.twitterApi.FavoritesCreate(post.RetweetedId ?? post.StatusId)
                        .IgnoreResponse()
                        .ConfigureAwait(false);

                    if (this._cfgCommon.RestrictFavCheck)
                    {
                        var status = await this.twitterApi.StatusesShow(post.RetweetedId ?? post.StatusId)
                            .ConfigureAwait(false);

                        if (status.Favorited != true)
                            throw new WebApiException("NG(Restricted?)");
                    }

                    this._favTimestamps.Add(DateTime.Now);

                    // TLでも取得済みならfav反映
                    if (this._statuses.ContainsKey(statusId))
                    {
                        var postTl = this._statuses[statusId];
                        postTl.IsFav = true;

                        var favTab = this._statuses.GetTabByType(MyCommon.TabUsageType.Favorites);
                        favTab.AddPostQueue(postTl);
                    }

                    // 検索,リスト,UserTimeline,Relatedの各タブに反映
                    foreach (var tb in this._statuses.GetTabsInnerStorageType())
                    {
                        if (tb.Contains(statusId))
                            tb.Posts[statusId].IsFav = true;
                    }

                    p.Report(string.Format(Properties.Resources.GetTimelineWorker_RunWorkerCompletedText15, 1, 1, 0));
                }
                catch (WebApiException)
                {
                    p.Report(string.Format(Properties.Resources.GetTimelineWorker_RunWorkerCompletedText15, 1, 1, 1));
                    throw;
                }

                // 時速表示用
                var oneHour = DateTime.Now - TimeSpan.FromHours(1);
                foreach (var i in MyCommon.CountDown(this._favTimestamps.Count - 1, 0))
                {
                    if (this._favTimestamps[i] < oneHour)
                        this._favTimestamps.RemoveAt(i);
                }

                this._statuses.DistributePosts();
            });

            if (ct.IsCancellationRequested)
                return;

            this.RefreshTimeline();

            if (this._curList != null && this._curTab != null && this._curTab.Text == tab.TabName)
            {
                using (ControlTransaction.Update(this._curList))
                {
                    var idx = tab.IndexOf(statusId);
                    if (idx != -1)
                        this.ChangeCacheStyleRead(post.IsRead, idx);
                }

                if (statusId == this._curPost.StatusId)
                    await this.DispSelectedPost(true); // 選択アイテム再表示
            }
        }