protected override void InitializeOnLoad()
 {
     base.InitializeOnLoad();
     //
     Task.Factory.StartNew(async() =>
     {
         try
         {
             if (_handler != null)
             {
                 ActionResult = await _handler.ExecuteAsync(CancellationTokenSource.Token, this);
             }
         }
         finally
         {
             DialogResult = DialogResult.OK;
         }
     },
                           CancellationTokenSource.Token);
 }