code: private void _initLogger(Map<String, ?> conf) {
          boolean logEnabled = (Boolean) RythmConfigurationKey.LOG_ENABLED.getConfiguration(conf);
          if (logEnabled) {
              ILoggerFactory factory = RythmConfigurationKey.LOG_FACTORY_IMPL.getConfiguration(conf);
              Logger.registerLoggerFactory(factory);
          } else {
              Logger.registerLoggerFactory(new NullLogger.Factory());
          }
      }
docs: /* -----------------------------------------------------------------------------
  Constructors, Configuration and Initializing
  -------------------------------------------------------------------------------