final Set<String> mergedIdSet = new HashSet<>();
        final List<SuggestItem> mergedList = new ArrayList<>(items.length);

        for (final SuggestItem item1 : items) {
            final String item1Id = item1.getId();
            if (mergedIdSet.contains(item1Id)) {
                continue;
            }

            SuggestItem mergedItem = item1;

    }

    /**
     * Merges two suggest items.
     * @param item1 The first suggest item.
     * @param item2 The second suggest item.
     * @return The merged suggest item.
     */
    public static SuggestItem merge(final SuggestItem item1, final SuggestItem item2) {
        if (!item1.getId().equals(item2.getId())) {
            throw new IllegalArgumentException("Item id is mismatch.");
        }

        assertArrayEquals(languages, item.getLanguages());
        assertEquals(1, item.getKinds().length);
        assertEquals(SuggestItem.Kind.QUERY, item.getKinds()[0]);
        assertEquals(50L, item.getQueryFreq());
        assertEquals(100L, item.getDocFreq());
        assertEquals(1.5f, item.getUserBoost(), 0.001f);
        assertNotNull(item.getTimestamp());
        assertNotNull(item.getId());
    }

    @Test

        assertEquals("123", testTransformer.getData(intData));

        // List data
        List<String> list = new ArrayList<>();
        list.add("item1");
        list.add("item2");
        TestAccessResultData<String> listData = new TestAccessResultData<>(list.toString().getBytes());
        Object retrievedList = testTransformer.getData(listData);

    }

    /**
     * Indexes a single suggest item.
     * @param item The suggest item to index.
     * @return The SuggestIndexResponse.
     */
    public SuggestIndexResponse index(final SuggestItem item) {
        return index(new SuggestItem[] { item });
    }

    /**
     * Indexes multiple suggest items.
     * @param items The suggest items to index.
     * @return The SuggestIndexResponse.
     */

        List<SuggestItem> items = defaultContentsParser.parseQueryLog(queryLog, supportedFields, tagFieldNames, roleFieldName,
                createDefaultReadingConverter(), createDefaultNormalizer());
        SuggestItem item = items.get(0);
        assertEquals("検索エンジン", item.getText());
        assertEquals(SuggestItem.Kind.QUERY, item.getKinds()[0]);
        assertEquals(1, item.getQueryFreq());
    }

            final boolean update) {
        final BulkRequestBuilder bulkRequestBuilder = client.prepareBulk();

        final SuggestItem[] mergedItems = mergeItems(items);
        if (mergedItems.length == 0) {
            return new SuggestWriterResult();
        }

        for (final SuggestItem item : mergedItems) {

                    readings[0] = l.toArray(new String[l.size()]);

                    if (items == null) {
                        items = new ArrayList<>(text.length() * fields.length / field.length());
                    }

                    final String[] langs = lang == null ? new String[] {} : new String[] { lang };
                    items.add(new SuggestItem(words, readings, new String[] { field }, 1L, 0, -1, tags, roles, langs,

    }

    @Test
    public void test_update() throws Exception {
        SuggestItem[] items = getItemSet1();
        suggester.indexer().index(items);
        suggester.refresh();

        SuggestItem[] items2 = getItemSet1();
        SuggestIndexResponse response = suggester.indexer().index(items2);

        assertFalse(response.hasError());

        suggester.refresh();

     * @return a list of suggest items parsed from the query log
     */
    List<SuggestItem> parseQueryLog(QueryLog queryLog, String[] fields, String[] tagFieldNames, String roleFieldName,
            ReadingConverter readingConverter, Normalizer normalizer);

    /**
     * Parses a document and extracts suggest items based on the provided fields and converters.
     *