public function macroTimestamp(Latte\MacroNode $node, Latte\PhpWriter $writer)
    {
        $class = get_called_class();
        return $writer->write('echo %escape(' . $class . '::timestamp(%node.arg, $_presenter->context->parameters['wwwDir']);');
    }

    public static function timestamp($file, $wwwDir)
    {
        $filepath = realpath($wwwDir . '/' . $node->args);
        if (file_exists($filepath)) {
            $mtime = filemtime($filepath);
            $mtime = dechex($mtime);

        } else {
            $mtime = 0; // Fail silently
        }

        return $filepath . '?' . $mtime;
    }