@VisibleForTesting
  SamzaApplicationState.SamzaAppStatus getAppStatus() {
    // make sure to only return a unmodifiable copy of the status variable
    return state.status;
  }
Stops all components of the JobCoordinator.
samza-core/src/main/java/org/apache/samza/clustermanager/ClusterBasedJobCoordinator.java