@VisibleForTesting
  boolean isImagePushed(Optional<ManifestAndDigest<ManifestTemplate>> manifestResult) {

    return !(JibSystemProperties.skipExistingImages() && manifestResult.isPresent());
  }
Run all steps and return a BuildResult after a build is completed.

@return a {@link BuildResult} with build metadata
@throws ExecutionException if an error occurred during asynchronous execution of steps
@throws InterruptedException if the build was interrupted while waiting for results
jib-core/src/main/java/com/google/cloud/tools/jib/builder/steps/StepsRunner.java