code: public void checkLoginAllowed() throws CmsAuthentificationException {
  
          if ((m_loginMessage != null) && (m_loginMessage.isLoginCurrentlyForbidden())) {
              // login message has been set and is active
              throw new CmsAuthentificationException(
                  Messages.get().container(Messages.ERR_LOGIN_FAILED_WITH_MESSAGE_1, m_loginMessage.getMessage()));
          }
      }
docs: Checks if a login is currently allowed.<p>
  
  In case no logins are allowed, an Exception is thrown.<p>
  
  @throws CmsAuthentificationException in case no logins are allowed