protected override async void OnAppearing()
 {
     base.OnAppearing();
     model.State      = ViewModel.Base.ModelState.Normal;
     model.MasterStep = 1;
     await model.Load();
 }
 protected override async void OnAppearing()
 {
     base.OnAppearing();
     model.State      = ViewModel.Base.ModelState.Normal;
     model.MasterStep = 1;
     MessagingCenter.Subscribe <MasterRackNewViewModel>(this, "BinTemplatesIsLoaded", BinTemplatesIsLoaded);
     MessagingCenter.Subscribe <MasterRackNewViewModel>(this, "UpdateRackView", UpdateRackView);
     MessagingCenter.Subscribe <BinsViewModel>(this, "Update", UpdateBinsViewModel);
     await model.Load();
 }