code: protected ActionResponse handleLoginUnauthorizedException(ActionRuntime runtime, LoginUnauthorizedException appEx) {
          assertLoginManagerPresent();
          if (appEx instanceof LoginFailureException) {
              saveErrors(getErrorsLoginFailureKey()); // needs to show message for user
          }
          final HtmlResponse response = redirectToLoginAction();
          appEx.mappingRedirectable(response);
          return response;
      }
docs: -----