ADBaseLibrary.DownloadManager.ReOrder C# (CSharp) Метод

        public void ReOrder(string id, string downid)
        {
            lock (_downloadslock)
            {
                DownloadItem dinfo = _downloads.FirstOrDefault(a => a.Id == id);
                DownloadItem rel = null;
                if (dinfo != null)
                {
                    _downloads.Remove(dinfo);
                    if (downid != null)
                        rel = _downloads.FirstOrDefault(a => a.Id == downid);
                    if (rel == null)
                        _downloads.Add(dinfo);
                    if (rel != null)
                        _downloads.Insert(_downloads.IndexOf(rel), dinfo);
                }
            }
            Save();
        }