public function addContentItem($label, $content, $url = null, $status = null, $active = false, array $cssClasses = [], array $attrs = [])
    {
        Checkers::checkUrl($url);
        $status === null || Checkers::checkStatus($status, null, true);
        $url    === null || $this->ulList = false;
        $this->list[] = [(string) $label, $url, (string) $content, $status, (bool) $active, $cssClasses, $attrs];
        $this->listCount++;
        return $this;
    }