RWTIOUResult Polling
RWTIOUResult enables your application to poll the IOU to determine if the result is available. You can then call the redeem() method without blocking, as shown in the following example.
// Get the IOU that will eventually contain the result
RWTIOUResult<RWFtpReply> iou = ftp.cd("pub");
while (!iou.redeemable()) {
// Go to sleep for a while, or do other things
}
// Redeem the available IOU result
RWFtpReply r = iou.redeem();
