this.type = type;
    }

    /**
     * Checks if this sitemap set is of type URLSET.
     * @return true if this is a URLSET, false otherwise
     */
    public boolean isUrlSet() {
        return URLSET.equals(type);
    }

    /**
     * Checks if this sitemap set is of type INDEX.
     * @return true if this is an INDEX, false otherwise
     */
    public boolean isIndex() {