public static function getCacheUrl()
 {
     if (empty(self::$_CFAO_CACHE_URL)) {
         $cache_url = WP_CONTENT_URL . '/cfao-cache/' . $_SERVER['HTTP_HOST'] . '/js/';
         self::$_CFAO_CACHE_URL = trailingslashit(apply_filters('cfao_script_cache_url', $cache_url));
     }
     return self::$_CFAO_CACHE_URL;
 }