addParts example

$parts = $body->getParts();
            if ($parts[0] instanceof RelatedPart) {
                $email = self::createEmailFromRelatedPart($message, $parts[0]);
            } elseif ($parts[0] instanceof AlternativePart) {
                $email = self::createEmailFromAlternativePart($message, $parts[0]);
            } elseif ($parts[0] instanceof TextPart) {
                $email = self::createEmailFromTextPart($message, $parts[0]);
            } else {
                throw new RuntimeException(sprintf('Unable to create an Email from an instance of "%s" as the body is too complex.', get_debug_type($message)));
            }

            return self::addParts($email, \array_slice($parts, 1));
        }

        throw new RuntimeException(sprintf('Unable to create an Email from an instance of "%s" as the body is too complex.', get_debug_type($message)));
    }

    private static function createEmailFromTextPart(Message $message, TextPart $part): Email
    {
        if ('text' === $part->getMediaType() && 'plain' === $part->getMediaSubtype()) {
            return (new Email(clone $message->getHeaders()))->text($part->getBody(), $part->getPreparedHeaders()->getHeaderParameter('Content-Type', 'charset') ?: 'utf-8');
        }
        if ('text' === $part->getMediaType() && 'html' === $part->getMediaSubtype()) {
            

$parts = $body->getParts();
            if ($parts[0] instanceof RelatedPart) {
                $email = self::createEmailFromRelatedPart($message, $parts[0]);
            } elseif ($parts[0] instanceof AlternativePart) {
                $email = self::createEmailFromAlternativePart($message, $parts[0]);
            } elseif ($parts[0] instanceof TextPart) {
                $email = self::createEmailFromTextPart($message, $parts[0]);
            } else {
                throw new RuntimeException(sprintf('Unable to create an Email from an instance of "%s" as the body is too complex.', get_debug_type($message)));
            }

            return self::addParts($email, \array_slice($parts, 1));
        }

        throw new RuntimeException(sprintf('Unable to create an Email from an instance of "%s" as the body is too complex.', get_debug_type($message)));
    }

    private static function createEmailFromTextPart(Message $message, TextPart $part): Email
    {
        if ('text' === $part->getMediaType() && 'plain' === $part->getMediaSubtype()) {
            return (new Email(clone $message->getHeaders()))->text($part->getBody(), $part->getPreparedHeaders()->getHeaderParameter('Content-Type', 'charset') ?: 'utf-8');
        }
        if ('text' === $part->getMediaType() && 'html' === $part->getMediaSubtype()) {