@Override
  public void updateJob(UUID jobId, PortabilityJob job) throws IOException {
    updateJob(jobId, job, null);
  }
Verifies a {@code PortabilityJob} already exists for {@code jobId}, and updates the entry to
{@code job}, within a {@code Transaction}.
extensions/cloud/portability-cloud-google/src/main/java/org/datatransferproject/cloud/google/GoogleJobStore.java