}

    /**
     * Sets the log level for the application.
     *
     * @param level The log level to set.
     */
    public void setLogLevel(final String level) {
        final Level logLevel = Level.toLevel(level, Level.WARN);
        System.setProperty(Constants.FESS_LOG_LEVEL, logLevel.toString());
        split(ComponentUtil.getFessConfig().getLoggingAppPackages(), ",")

        CrawlerSystemException topLevel = new CrawlerSystemException("Top level", level1);

        // Verify chain
        assertSame(level1, topLevel.getCause());
        assertSame(level2, topLevel.getCause().getCause());
        assertSame(level3, topLevel.getCause().getCause().getCause());
        assertNull(topLevel.getCause().getCause().getCause().getCause());

        // Verify messages