code: public ChangeMessageVisibilityResult changeMessageVisibilitySync(ChangeMessageVisibilityRequest request) {
          Future<ChangeMessageVisibilityResult> future = sendBuffer.changeMessageVisibility(request, null);
          return waitForFuture(future);
      }
docs: Changes visibility of a message in SQS. Does not return until a confirmation from SQS has
  been received.
  @return