public AuthedDownloader(Authorization auth, string cachePath = null)
 {
     Auth   = auth;
     Client = cachePath == null ? new Client() : new CachedDownloadClient(cachePath);
 }
 public AuthedDownloader(string cachePath = null)
 {
     Auth   = new Authorization();
     Client = cachePath == null ? new Client() : new CachedDownloadClient(cachePath);
 }