@Override
  public void restartJob() {
    LOG.info("Job restart signalled, but job restart is no-op for this class");
  }
Placeholder implementation for {@link JobRestartSignal}.
If a use case requires job restarts, then a real implementation should be used.
samza-core/src/main/java/org/apache/samza/coordinator/lifecycle/NoOpJobRestartSignal.java