Is AWS SDK `PutObjectResult` metadata not holding the content length value?

I am successfully storing objects to S3. As a result of PutObjectRequest it returns PutObjectResult, which has a getMetadata() method. However, the metadata it returns is holding some values and misses others that I would expect to be there. In particular it misses the content length value, though it is explicitly assigned to PutObjectRequest.

For instance, this sample code:

  val client: AmazonS3 = ???

  val contentBytes = "Test content".getBytes
  val inputStream: InputStream = new ByteArrayInputStream(contentBytes)

  val metadata = new ObjectMetadata
  metadata.setContentLength(contentBytes.length)

  val putRequest = new PutObjectRequest("bucketName", "key", inputStream, metadata)
    .withStorageClass(StorageClass.valueOf("ReducedRedundancy"))

  val putObjectResult = client.putObject(putRequest)

  println(s"Storage class: ${putObjectResult.getMetadata.getStorageClass}; Length: ${putObjectResult.getMetadata.getContentLength}")

would return the following: Storage class: REDUCED_REDUNDANCY; Length: 0

Is it a bug, am I doing something wrong, or is it expected behaviour?