PushContainerConfigurationStep.java

class PushContainerConfigurationStep
  /*(...)*/
  @Override
  public AsyncStep<PushBlobStep> call() throws ExecutionException {
    ListenableFuture<PushBlobStep> pushBlobStepFuture =
        Futures.whenAllSucceed(
                authenticatePushStep.getFuture(), NonBlockingSteps.get(buildImageStep).getFuture())
            .call(this::afterBuildConfigurationFutureFuture, listeningExecutorService);
    return () -> pushBlobStepFuture;
  }
  
  private PushBlobStep afterBuildConfigurationFutureFuture()/*(...)*/ {
  /*(...)*/
      Image<CachedLayer> image = NonBlockingSteps.get(NonBlockingSteps.get(buildImageStep));
      Blob containerConfigurationBlob =
          new ImageToJsonTranslator(image).getContainerConfigurationBlob();
      CountingDigestOutputStream digestOutputStream =
          new CountingDigestOutputStream(ByteStreams.nullOutputStream());
      containerConfigurationBlob.writeTo(digestOutputStream);

      BlobDescriptor blobDescriptor = digestOutputStream.toBlobDescriptor();

      return new PushBlobStep(/*(...)*/);
    }
  }
}