docs: public void releaseExternalResources() {
  
          if (!isClosed.get()) {
              logger.info("Releasing all ParallelClient resources... ");
              ActorConfig.shutDownActorSystemForce();
              httpClientStore.shutdown();
              tcpSshPingResourceStore.shutdown();
              cleanWaitTaskQueue();
              cleanInprogressJobMap();
              isClosed.set(true);
              logger.info("Have released all ParallelClient resources "
                      + "(actor system + async+sync http client + task queue)"
                      + "\nNow safe to stop your application.");
  
          } else {
              logger.debug("NO OP. ParallelClient resources have already been released.");
          }
  
      }