this.timestamp = timestamp;
    }

    /**
     * Sets the query frequency of the suggest item.
     * @param queryFreq The query frequency to set.
     */
    public void setQueryFreq(final long queryFreq) {
        this.queryFreq = queryFreq;
    }

    /**
     * Sets the document frequency of the suggest item.
     * @param docFreq The document frequency to set.
     */

      "format": "epoch_millis"
    },
    "docFreq": {
      "type": "long"
    },
    "fields": {
      "type": "keyword"
    },
    "kinds": {
      "type": "keyword"
    },
    "queryFreq": {
      "type": "long"
    },
    "roles": {
      "type": "keyword"
    },
    "languages": {
      "type": "keyword"
    },
    "score": {
      "type": "double"
    },
    "tags": {

    public static final String READING_PREFIX = "reading_";
    /** The score field. */
    public static final String SCORE = "score";
    /** The query frequency field. */
    public static final String QUERY_FREQ = "queryFreq";
    /** The document frequency field. */
    public static final String DOC_FREQ = "docFreq";
    /** The user boost field. */
    public static final String USER_BOOST = "userBoost";
    /** The kinds field. */

        // Test creating bulk line for indexing
        SuggestItem item = new SuggestItem(new String[] { "test text" }, new String[][] { { "reading1" }, { "reading2" } },
                new String[] { "field1", "field2" }, 10, // queryFreq
                5, // docFreq
                2.0f, // userBoost
                new String[] { "tag1", "tag2" }, new String[] { "role1" }, new String[] {}, // languages
                SuggestItem.Kind.DOCUMENT);

        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);
        assertTrue(suggestItem.getDocFreq() >= 0);

        // Check readings

        for (int i = 0; i < readings.length; i++) {
            secondLine.put("reading_" + i, readings[i]);
        }

        secondLine.put("fields", item.getFields());
        secondLine.put("queryFreq", item.getQueryFreq());
        secondLine.put("docFreq", item.getDocFreq());
        secondLine.put("userBoost", item.getUserBoost());

        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"));

        queryBuilder.mustNot(QueryBuilders.existsQuery(FieldNames.READING_PREFIX + "1"));
        queryBuilder.must(QueryBuilders.rangeQuery(FieldNames.QUERY_FREQ).gte(queryFreqThreshold));
        if (!tags.isEmpty()) {
            queryBuilder.must(QueryBuilders.termsQuery(FieldNames.TAGS, tags));
        }
        if (!roles.isEmpty()) {

        final long start = System.currentTimeMillis();

        final SuggestDeleteResponse deleteResponse = deleteByQuery(QueryBuilders.boolQuery()
                .must(QueryBuilders.rangeQuery(FieldNames.QUERY_FREQ).gte(1))
                .mustNot(QueryBuilders.matchPhraseQuery(FieldNames.KINDS, SuggestItem.Kind.DOCUMENT.toString()))
                .mustNot(QueryBuilders.matchPhraseQuery(FieldNames.KINDS, SuggestItem.Kind.USER.toString())));

                .modifier(FieldValueFactorFunction.Modifier.LOG2P)
                .setWeight(1.0F)));
        flist.add(new FunctionScoreQueryBuilder.FilterFunctionBuilder(ScoreFunctionBuilders.fieldValueFactorFunction(FieldNames.QUERY_FREQ)
                .missing(0.1f)
                .modifier(FieldValueFactorFunction.Modifier.LOG2P)
                .setWeight(1.0F)));
        flist.add(new FunctionScoreQueryBuilder.FilterFunctionBuilder(