public function render($template, array $viewData = [])
    {
        $filePath = $this->finder->getTemplatePath($template);
        if ($filePath == false) {
            throw new InvalidArgumentException("Can't load template '$template'");
        }
        ob_start();
        extract($viewData);
        include($filePath);
        $contents = ob_get_contents();
        ob_end_clean();
        return $contents;
    }