}

    /**
     * Gets the fields that can be used for faceted search.
     *
     * @return array of field names that can be used for faceted search
     */
    public String[] getFacetFields() {
        return facetFields;
    }

    /**
     * Sets the fields that can be used for faceted search.
     * Also updates the facetFieldSet for O(1) lookup performance.
     *