@Override
  public int hashCode() {
    return Objects.hash(jobName, jobId, containerName, execEnvironmentContainerId, samzaEpochId, source,
        version, samzaVersion, host, time, resetTime);
  }
Epoch id for the application, which is consistent across all components of a single deployment attempt.
This may be empty, since this field was added to this class after the initial version.
samza-core/src/main/java/org/apache/samza/metrics/reporter/MetricsHeader.java