return SuggestItemSerializer.toSource(this);
    }

    /**
     * Parses a source map and returns a SuggestItem instance.
     * @param source The source map.
     * @return A SuggestItem instance.
     */
    public static SuggestItem parseSource(final Map<String, Object> source) {
        return SuggestItemSerializer.fromSource(source);
    }

    /**

        SuggestItem suggestItem = elevateWord.toSuggestItem();

        assertNotNull(suggestItem);
        assertEquals(word, suggestItem.getText());
        assertEquals(boost, suggestItem.getUserBoost(), 0.001f);
        // The queryFreq and docFreq might be handled differently by SuggestItem
        assertTrue(suggestItem.getQueryFreq() >= 0);

        String[] languages = { "en" };
        long docFreq = 10L;
        long queryFreq = 5L;
        float userBoost = 1.5f;

        SuggestItem item =
                new SuggestItem(text, readings, fields, docFreq, queryFreq, userBoost, tags, roles, languages, SuggestItem.Kind.DOCUMENT);

        Map<String, Object> source = SuggestItemSerializer.toSource(item);

        assertNotNull(source);

        words.add("test");

        List<SuggestItem> items = new ArrayList<>();
        String[][] readings = new String[1][];
        readings[0] = new String[] { "test" };
        items.add(new SuggestItem(new String[] { "test" }, readings, new String[] { "content" }, 1, 0, -1, new String[] { "tag1" },
                new String[] { SuggestConstants.DEFAULT_ROLE }, null, SuggestItem.Kind.DOCUMENT));

                items.add(new SuggestItem(words, readings, new String[] { field }, 0, 1, -1, tags, roles, null, SuggestItem.Kind.QUERY));
            }
        } catch (final IOException e) {
            throw new SuggesterException("Failed to create SuggestItem from query log.", e);
        }

        return items;
    }

    @Override

        List<SuggestItem> items =
                parser.parseQueryLog(queryLog, supportedFields, tagFieldNames, roleFieldName, defaultReadingConverter, defaultNormalizer);

        assertTrue(items.size() > 0);
        SuggestItem item = items.get(0);
        assertTrue("Should have multiple tags", item.getTags().length >= 2);
    }

        SuggestItem[] items = new SuggestItem[1];
        String[][] readings = new String[1][];
        readings[0] = new String[] { "test" };
        items[0] = new SuggestItem(new String[] { "test" }, readings, new String[] { "content" }, 0, 15, -1, new String[] { "tag1" },
                new String[] { SuggestConstants.DEFAULT_ROLE }, new String[] { "en" }, SuggestItem.Kind.QUERY);

     * @return The SuggestIndexResponse
     */
    public SuggestIndexResponse index(final String index, final SuggestItem[] items, final String[] badWords) {
        final SuggestItem[] filteredItems = Stream.of(items).filter(item -> !item.isBadWord(badWords)).toArray(SuggestItem[]::new);

        if (logger.isDebugEnabled()) {

        SuggestItem.Kind[] result = SuggestItem.concatKinds(new SuggestItem.Kind[0], new SuggestItem.Kind[0]);

        assertEquals(0, result.length);
    }

    @Test
    public void test_concatKinds_firstEmpty() {
        SuggestItem.Kind[] kinds2 = { SuggestItem.Kind.QUERY };

        SuggestItem.Kind[] result = SuggestItem.concatKinds(new SuggestItem.Kind[0], kinds2);

        SuggestItem item3 = new SuggestItem(new String[] { "テスト" }, readings, new String[] { "content" }, 3, 0, -1, new String[] { "tag1" },
                new String[] { SuggestConstants.DEFAULT_ROLE }, null, SuggestItem.Kind.DOCUMENT);
        SuggestItem item4 = new SuggestItem(new String[] { "テスト" }, readings, new String[] { "content" }, 4, 0, -1, new String[] { "tag1" },