private void Instance_OnSMStoppedEvent(object sender,
                                        Interop.SuperMemo.Core.SMProcessArgs e)
 {
     SyncContext.Send(
         delegate { Shutdown(); },
         null);
 }
 private Task Instance_OnSMStoppedEvent(object sender,
                                        Interop.SuperMemo.Core.SMProcessArgs e)
 {
     return(Dispatcher.InvokeAsync(Shutdown).Task);
 }