public function render($template, array $additionalVariables = null)
    {
        $variables = $this->getVariables();

        // Pass the helper to the template:
        $variables["tpl"] = $this;

        if ($additionalVariables !== null) {
            $variables = array_replace($variables, $additionalVariables);
        }

        call_user_func(function () {
            extract(func_get_arg(1));
            require func_get_arg(0);
        }, $template, $variables);
    }