code: public static String getCurrentId()
    {
      SystemManager system = getCurrent();
  
      if (system == null) {
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
  
        throw new IllegalStateException(L.l("{0} is not available in this context.\n  {1}",
                                            SystemManager.class.getSimpleName(),
                                            loader));
      }
  
      return system.getId();
    }
docs: Returns the current system id.