/**
* Goes recursively through all parts of multi part and tries to retrieve content in required format
*
* @param PartInterface $multipart
* @param string $format
*
* @return Content|null Returns null if given part is not multipart or when content of required format not found
*/
protected function getMultipartContentRecursively(PartInterface $multipart, $format)
{
if ($multipart->isMultipart()) {
foreach ($multipart as $part) {
if ($part->isMultipart()) {
return $this->getMultipartContentRecursively($part, $format);
}
$contentTypeHeader = $this->getPartContentType($part);
if ($contentTypeHeader->getType() === $format) {
return $this->extractContent($part);
}
}
}
}