code: private static String localize(Logger logger, String message) {
          ResourceBundle bundle = logger.getResourceBundle();
          try {
              return bundle != null ? bundle.getString(message) : message;
          } catch (MissingResourceException ex) {
              //string not in the bundle
              return message;
          }
      }
docs: Retrieve localized message retrieved from a logger's resource
  bundle.
  
  @param logger the Logger
  @param message the message to be localized