protected function hasSelectorPlaceholder($selector)
    {
        if (! is_array($selector)) {
            return false;
        }

        foreach ($selector as $parts) {
            foreach ($parts as $part) {
                if (is_array($part)) {
                    return false;
                }
                if (strlen($part) && '%' === $part[0]) {
                    return true;
                }
            }
        }

        return false;
    }