public override void RegisterCallback(IGalleryServiceCallbackProxy callbackProxy)
        {
            GalleryServiceService service = null;

            if (_reference.TryGetTarget(out service))
            {
                service.RegisterCallback(callbackProxy);
            }
        }
 public void RegisterCallback(IGalleryServiceCallbackProxy callbackProxy)
 {
     _callbackProxy = callbackProxy;
 }