internal static void UnsafeLaunchBrowser(Uri uri, string targetFrame = null)
 {
     if (Application.Current != null && Application.Current.CheckAccess())
     {
         IBrowserCallbackServices browserCallbackServices = Application.Current.BrowserCallbackServices;
         if (browserCallbackServices != null)
         {
             browserCallbackServices.DelegateNavigation(BindUriHelper.UriToString(uri), targetFrame, AppSecurityManager.GetHeaders(uri));
             return;
         }
     }
     AppSecurityManager.ShellExecuteDefaultBrowser(uri);
 }