protected function processParts(array $parts)
    {
        $comment = '';
        foreach ($parts as $part) {
            // order is important here - CommentPart extends LiteralPart
            if ($part instanceof CommentPart) {
                $comment .= '(' . $part->getComment() . ')';
            } elseif ($part instanceof LiteralPart) {
                $comment .= '"' . $part->getValue() . '"';
            } else {
                $comment .= $part->getValue();
            }
        }
        return [$this->partFactory->newCommentPart($comment)];
    }