docs: public void waitForCompletion()
              throws AmazonClientException, AmazonServiceException, InterruptedException {
          try {
              Object result = null;
              while (!monitor.isDone() || result == null) {
                  Future<?> f = monitor.getFuture();
                  result = f.get();
              }
          } catch (ExecutionException e) {
              rethrowExecutionException(e);
  
          }
      }