public function insertProtect(array $matches = [])
    {
        $gen = md5(mt_rand());

        /** @var ISession $s */
        $s = (new SessionInjector)->build();
        $s->csrf = array_merge(is_array($s->csrf) ? $s->csrf : [], [md5($gen)]);

        return $matches[1].'<input type="hidden" name="csrf" value="'.$gen.'" />'.$matches[2].$matches[3];
    }