/// <summary>
 /// Downloads the file.
 /// </summary>
 /// <param name="navigator">The navigator.</param>
 /// <param name="downloadUri">The download URI.</param>
 /// <param name="saveTextPath">The save text path.</param>
 /// <param name="proxy">The proxy.</param>
 private void DownloadFile(INavigator navigator, string downloadUri, string saveTextPath, Uri proxy)
 {
     if (proxy != null)
     {
         ProxyConfiguration.SetApplicationProxy(proxy);
     }
     navigator.Show(
         delegate(WebDownloaderViewModel vm)
     {
         vm.DownloadUri  = downloadUri;
         vm.SaveTextPath = saveTextPath;
     });
 }