/**
     * 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))

     */
    public SuggestDeleteResponse deleteQueryWords() {
        if (logger.isInfoEnabled()) {
            logger.info("Deleting query words: index={}", index);
        }
        return deleteWordsByKind(FieldNames.QUERY_FREQ, SuggestItem.Kind.QUERY, item -> item.setQueryFreq(0), SuggestItem.Kind.DOCUMENT,
                SuggestItem.Kind.USER);
    }

    /**
     * Common method to delete words by kind.