final public static function checkLibrariesRequired()
    {
        $base =  __DIR__."/../../";
        foreach (self::$libs as $lib => $val) {
            if (!is_dir($base.$lib) || !self::checkIsReadable($base.$lib) ||
                !self::checkIsWritable($base.$lib) || self::isDirEmpty($base.$lib)) {
                return (json_encode(array("code" => 500, "results" => "NOK", "libsr" => $lib, "msg" => $val)));
            }
        }

        foreach (self::$php_extensions as $lib => $val) {
            if (!extension_loaded($lib)) {
                return (json_encode(array("code" => 500, "results" => "NOK", "libsr" => $lib, "msg" => $val)));
            }
        }

        return (json_encode(array("code" => 200, "results" => "OK")));
    }