@Test
    public void test_parseSource_completeData() {
        Map<String, Object> source = new HashMap<>();
        source.put(FieldNames.TEXT, "test");
        source.put(FieldNames.QUERY_FREQ, 100L);
        source.put(FieldNames.DOC_FREQ, 50L);
        source.put(FieldNames.USER_BOOST, 2.0f);
        source.put(FieldNames.READING_PREFIX + "0", Arrays.asList("reading1"));

        }

        final long updatedQueryFreq = mergeFrequency(existingSource, FieldNames.QUERY_FREQ, item.getQueryFreq());
        map.put(FieldNames.QUERY_FREQ, updatedQueryFreq);

        final long updatedDocFreq = mergeFrequency(existingSource, FieldNames.DOC_FREQ, item.getDocFreq());
        map.put(FieldNames.DOC_FREQ, updatedDocFreq);

        Map<String, Object> map = item.toEmptyMap();

        assertNotNull(map);
        assertEquals("", map.get(FieldNames.TEXT)); // Empty string for empty map
        assertEquals(0L, map.get(FieldNames.QUERY_FREQ));
        assertEquals(0L, map.get(FieldNames.DOC_FREQ));
        assertEquals(1.0f, map.get(FieldNames.USER_BOOST));
        assertNotNull(map.get(FieldNames.READING_PREFIX + "0"));

        map.put(FieldNames.LANGUAGES, new String[] {});
        map.put(FieldNames.KINDS, new String[] {});
        map.put(FieldNames.SCORE, 1.0F);
        map.put(FieldNames.QUERY_FREQ, 0L);
        map.put(FieldNames.DOC_FREQ, 0L);
        map.put(FieldNames.USER_BOOST, 1.0F);
        map.put(FieldNames.TIMESTAMP, DateTimeFormatter.ISO_INSTANT.format(ZonedDateTime.now()));
        return map;
    }

    /**
     * Returns the number of query words in the suggestion index.
     * @return The number of query words.
     */
    public long getQueryWordsNum() {
        return getNum(QueryBuilders.rangeQuery(FieldNames.QUERY_FREQ).gte(1));
    }

    private long getNum(final QueryBuilder queryBuilder) {
        final SearchResponse searchResponse = client.prepareSearch()
                .setIndices(getSearchAlias(index))