public function saveAttachments(
        $attach_dir,
        $include_inline = true,
        $filenameStrategy = self::ATTACHMENT_DUPLICATE_SUFFIX
    ) {
        $attachments = $this->getAttachments($include_inline);

        $attachments_paths = [];
        foreach ($attachments as $attachment) {
            $attachments_paths[] = $attachment->save($attach_dir, $filenameStrategy);
        }

        return $attachments_paths;
    }