private static AuthorizedNavigationAttribute GetAuthorizedAttributeData(this NavigationTypeRegistration registration)
 => registration.Type.GetCustomAttributes(typeof(AuthorizedNavigationAttribute), false).FirstOrDefault() as AuthorizedNavigationAttribute;
 public static bool IsAuthorized(this NavigationTypeRegistration registration)
 => registration.GetAuthorizedAttributeData() != null;
 public static string GetAlternativeNavigationTag(this NavigationTypeRegistration registration)
 => registration.GetAuthorizedAttributeData()?.AlternativePageTag;