public static <X extends AmazonWebServiceRequest> X appendMultipartUserAgent(X request) {
        request.getRequestClientOptions().appendUserAgent(USER_AGENT_MULTIPART);
        return request;
    }
Shutdown without interrupting the threads involved, so that, for example,
any upload in progress can complete without throwing
{@link AbortedException}.
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/transfer/TransferManager.java