code: @Override
    public synchronized boolean addLogger(Logger logger)
    {
      EnvironmentLogger envLogger = addLogger(logger.getName(),
                                              logger.getResourceBundleName());
      
      // handle custom logger
      if (! logger.getClass().equals(Logger.class)) {
        return envLogger.addCustomLogger(logger);
      }
  
      return false;
    }
docs: Adds a logger.