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);

                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.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" },

        readings3[0] = new String[] { "both" };
        items[2] = new SuggestItem(new String[] { "両方" }, readings3, new String[] { "content" }, 1L, 1L, -1.0f, new String[] { "tag1" },
                new String[] { SuggestConstants.DEFAULT_ROLE }, null, SuggestItem.Kind.DOCUMENT);
        items[2].setKinds(new SuggestItem.Kind[] { SuggestItem.Kind.DOCUMENT, SuggestItem.Kind.QUERY });

        suggester.indexer().index(items);

    }

    @Test
    public void testConcatKinds() {
        // Test static concatKinds method
        SuggestItem.Kind[] kinds1 = { SuggestItem.Kind.QUERY };
        SuggestItem.Kind[] kinds2 = { SuggestItem.Kind.DOCUMENT, SuggestItem.Kind.QUERY };

        SuggestItem.Kind[] result = SuggestItem.concatKinds(kinds1, kinds2);

        assertNotNull(result);

        final SuggestItem.Kind[] itemKinds = new SuggestItem.Kind[kinds.size()];
        for (int i = 0; i < kinds.size(); i++) {
            final String kind = kinds.get(i);
            if (kind.equals(SuggestItem.Kind.DOCUMENT.toString())) {
                itemKinds[i] = SuggestItem.Kind.DOCUMENT;
            } else if (kind.equals(SuggestItem.Kind.QUERY.toString())) {

            items.add(new SuggestItem(new String[] { "マルチワード" + i, "fuga" }, readings, new String[] { "content" }, 0, 15 + i, -1, tags,
                    roles, null, SuggestItem.Kind.QUERY));
        }

        return items.toArray(new SuggestItem[items.size()]);
    }

    private SuggestItem[] getItemSet2() {
        List<SuggestItem> items = new ArrayList<>();

        {