private function protectedInclude()
    {
        $_tpl = $this;

        // View Helpers:
        // * Include another view into the current view:
        $_view = function ($tplName, $params = []) use ($_tpl) {
            $tplCopy = clone $_tpl; // Don't want to mess with the calling template's settings.
            echo($tplCopy->render($tplName, $params));
            unset($tplCopy);
        };
        // * Encode html for a 'Safe String'.
        $_ss = function ($str) {
            return htmlspecialchars($str, ENT_QUOTES);
        };

        // Extract template parameters into this local namespace.
        $allParams = (object) array_merge((array)self::$staticParams, (array)$this->params);
        extract(get_object_vars($allParams));
        unset($allParams);

        // Included template has access to variables local to this function.
        include($this->templateFile);
    }