Can I disable master in Xamarin.Forms MasterDetailPage

gistfile1.cs

public static Page GetMainPage()
		{	
			var masterDetailPage = new MasterDetailPage ();
			masterDetailPage.Master = new MenuPage (masterDetailPage);

			if(User.IsNotAuthenticated){
				//HERE IS WHERE I WOULD LIKE TO DISABLE THE MASTER
				masterDetailPage.Detail = new NavigationPage (new LoginPage ()) { };

				//This does not do anything.
				masterDetailPage.Master.IsEnabled = false;
			} else {
				masterDetailPage.Detail = new NavigationPage (new CreateWantPage ()) { };
			}


			return masterDetailPage;
		}