final Level logLevel = Level.toLevel(level, Level.WARN);
        System.setProperty(Constants.FESS_LOG_LEVEL, logLevel.toString());
        split(ComponentUtil.getFessConfig().getLoggingAppPackages(), ",")
                .of(stream -> stream.map(String::trim).filter(StringUtil::isNotEmpty).forEach(s -> Configurator.setLevel(s, logLevel)));
    }

    /**
     * Gets the current log level.
     *

     * comment: Application packages for logging.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getLoggingAppPackages();

    /**
     * Get the value for the key 'logging.search.docs.enabled'. <br>
     * The value is, e.g. true <br>
     * comment: Whether to enable search docs logging.