} else {
                System.clearProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);
            }
        }
    }

    public void test_getSearchEngineHttpAddress_withEmptyString() {
        String originalValue = System.getProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS);

        try {
            System.setProperty(Constants.FESS_SEARCH_ENGINE_HTTP_ADDRESS, "");