    public function closestParentOfType($str)
    {
        $str = strtolower($str);
        $currentEl = $this;

        while (strtolower($currentEl->getTagName()) != $str && $currentEl->hasParent()) {
            $currentEl = $currentEl->getParent();
        }

        if (strtolower($currentEl->getTagName()) != $str) {
            return null;
        } else {
            return $currentEl;
        }
    }
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.