final long start = System.currentTimeMillis();

        final SuggestDeleteResponse deleteResponse = deleteByQuery(QueryBuilders.boolQuery()
                .must(QueryBuilders.rangeQuery(FieldNames.DOC_FREQ).gte(1))
                .mustNot(QueryBuilders.matchPhraseQuery(FieldNames.KINDS, SuggestItem.Kind.QUERY.toString()))

     */
    public long getDocumentWordsNum() {
        return getNum(QueryBuilders.rangeQuery(FieldNames.DOC_FREQ).gte(1));
    }

    /**
     * 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));
    }

        queryBuilder.must(QueryBuilders.termQuery(FieldNames.KINDS, SuggestItem.Kind.QUERY.toString()));
        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()) {