void ViewProviderViewClosed(object sender, ViewClosedEventArgs e)
        {
            //TODO write test around context/view cleanup
            customTaskPaneRegister.Cleanup(e.View);

            CleanupViewModel(e.Context);
            viewProvider.CleanupReferencesTo(e.View, e.Context);
        }
        void ViewProviderViewClosed(object sender, ViewClosedEventArgs e)
        {
            VstoContribLog.Debug(_ => _("ViewProvider.ViewClosed Raised, View: {0}, Context: {1}",
                                        e.View.ToLogFormat(), e.Context.ToLogFormat()));
            //TODO write test around context/view cleanup
            customTaskPaneRegister.Cleanup(e.View);

            CleanupViewModel(e.Context);
            viewProvider.CleanupReferencesTo(e.View, e.Context);
        }