final String logLevel = systemHelper.getLogLevel();
        try {
            systemHelper.setLogLevel("DEBUG");
            assertEquals("DEBUG", systemHelper.getLogLevel());
            systemHelper.setLogLevel("INFO");
            assertEquals("INFO", systemHelper.getLogLevel());
            systemHelper.setLogLevel("WARN");
            assertEquals("WARN", systemHelper.getLogLevel());
            systemHelper.setLogLevel("ERROR");

        form.storageBucket = fessConfig.getStorageBucket();
        form.logLevel = ComponentUtil.getSystemHelper().getLogLevel().toUpperCase();
    }

    private void updateProperty(final String key, final String value) {
        systemProperties.setProperty(key, value == null ? StringUtil.EMPTY : value);
    }

                .of(stream -> stream.map(String::trim).filter(StringUtil::isNotEmpty).forEach(s -> Configurator.setLevel(s, logLevel)));
    }

    public String getLogLevel() {
        return System.getProperty(Constants.FESS_LOG_LEVEL, Level.WARN.toString());
    }

    public File createTempFile(final String prefix, final String suffix) {
        try {