public void SetDownloadDirectory(string path)
 {
     if (DownloadDirectory != "")
     {
         throw new NotImplementedException("Changing of download directory while it has been set before is not supported.");
     }
     DownloadDirectory = path;
     _osuDownloader    = new OsuDownloader(DownloadDirectory, 3);
     _osuDownloader.ProgressUpdated += OsuDownloaderOnProgressUpdated;
 }