@Override
  protected Scheduler scheduler() {
    return scheduler;
  }
A service that polls storage for a job to process in two steps: <br> (1) find an unassigned job
for this transfer worker <br> (2) wait until the job is ready to process (i.e. creds are
available)
portability-transfer/src/main/java/org/datatransferproject/transfer/JobPollingService.java