/**
  * Creates an UploadState object for a multipart upload by querying the
  * service for the specified upload's information.
  *
  * @param S3ClientInterface $client   S3Client used for the upload.
  * @param string            $bucket   Bucket for the multipart upload.
  * @param string            $key      Object key for the multipart upload.
  * @param string            $uploadId Upload ID for the multipart upload.
  *
  * @return UploadState
  */
 public static function getStateFromService(S3ClientInterface $client, $bucket, $key, $uploadId)
 {
     $state = new UploadState(['Bucket' => $bucket, 'Key' => $key, 'UploadId' => $uploadId]);
     foreach ($client->getPaginator('ListParts', $state->getId()) as $result) {
         // Get the part size from the first part in the first result.
         if (!$state->getPartSize()) {
             $state->setPartSize($result->search('Parts[0].Size'));
         }
         // Mark all the parts returned by ListParts as uploaded.
         foreach ($result['Parts'] as $part) {
             $state->markPartAsUploaded($part['PartNumber'], ['PartNumber' => $part['PartNumber'], 'ETag' => $part['ETag']]);
         }
     }
     $state->setStatus(UploadState::INITIATED);
     return $state;
 }