ComponentUtil.setFessConfig(new FessConfig.SimpleImpl() {
            private static final long serialVersionUID = 1L;

            @Override
            public String getCrawlerDocumentHtmlDefaultLang() {
                return "en";
            }
        });
        assertEquals("en", systemHelper.normalizeHtmlLang("ja"));
    }

    @Test
    public void test_normalizeLang() {

Shinsuke Sugaya <******@****.***> 1773442886 +0900

     * @return The normalized language string.
     */
    public String normalizeHtmlLang(final String value) {
        final String defaultLang = ComponentUtil.getFessConfig().getCrawlerDocumentHtmlDefaultLang();
        if (StringUtil.isNotBlank(defaultLang)) {
            return defaultLang;
        }

        return normalizeLang(value);
    }

    /**
     * Normalizes a language string.