Shinsuke Sugaya <******@****.***> 1514783567 +0900

        assertArrays(new String[] { "ja" }, fessConfig.normalizeQueryLanguages(new String[] { "ja-jp" }));
        assertArrays(new String[] { "ja" }, fessConfig.normalizeQueryLanguages(new String[] { "ja_JP" }));
        assertArrays(new String[] { "ja", "zh-cn" }, fessConfig.normalizeQueryLanguages(new String[] { "ja", "zh" }));

        // Test that method is case sensitive (as per implementation)
        assertNull(languageHelper.getSupportedLanguage("JA"));
        assertNull(languageHelper.getSupportedLanguage("EN"));
        assertEquals("ja", languageHelper.getSupportedLanguage("ja"));
        assertEquals("en", languageHelper.getSupportedLanguage("en"));
    }

    @Test
    public void test_updateDocument_emptyLangFields() {

        value = " ja ";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "ja-JP";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "ja_JP";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "ja_JP_AAA";
        assertEquals("ja", systemHelper.normalizeLang(value));

        value = "zh";

    @Test
    public void test_serializeParameters() {
        RequestParameter[] params = new RequestParameter[] { new RequestParameter("q", new String[] { "test" }),
                new RequestParameter("lang", new String[] { "en", "ja" }) };
        String encoded = searchHelper.serializeParameters(params);
        assertNotNull(encoded);
        byte[] compressed = Base64.getUrlDecoder().decode(encoded);

        // Test convert with multiple languages
        String text = "test text";
        String field = "content";

        List<String> results = converter.convert(text, field, "en", "ja");

        assertNotNull(results);
        // With multiple languages, should use ReadingConverterChain
    }

    @Test
    public void testConvertWithEmptyText() throws IOException {

        // Test convert with multiple languages
        converter.init();
        String text = "test";
        String field = "content";

        List<String> readings = converter.convert(text, field, "en", "ja", "fr");

        assertNotNull(readings);
        assertEquals(3, readings.size());
        assertEquals("TEST_en", readings.get(0));
        assertEquals("TEST_ja", readings.get(1));

        value.clear();

        List<String> keys = Arrays.asList("test_2", "test_0", "lang", "test_1");
        value.put(keys.get(0), true);
        value.put(keys.get(1), 1000);
        value.put(keys.get(2), "ja");
        value.put(keys.get(3), "str");
        docMap = new DocMap(value);
        assertFalse(docMap.isEmpty());

        Set<Map.Entry<String, Object>> actual = docMap.entrySet();

        assertTrue(fieldSet.contains("field3"));
    }

    @Test
    public void testMerge_languages() {
        SuggestItem item1 = createItemWithLanguages("text", "en", "ja");
        SuggestItem item2 = createItemWithLanguages("text", "ja", "zh");

        SuggestItem merged = SuggestItemMerger.merge(item1, item2);

        String[] languages = merged.getLanguages();

```

**Optional configurations:**

If you create online help documentation:
```properties
online.help.supported.langs=ja,sv  # Add your language
```

If you have forum support:
```properties
forum.supported.langs=en,ja,sv  # Add your language
```