@Override
  public AccountService getAccountService() {
    try {
      ScheduledExecutorService scheduler =
          accountServiceConfig.updaterPollingIntervalMs > 0 ? Utils.newScheduler(1, updaterThreadPrefix, false) : null;
      HelixAccountService accountService =
          new HelixAccountService(getHelixStore(accountServiceConfig.zkClientConnectString, storeConfig),
              accountServiceMetrics, notifier, scheduler, accountServiceConfig);
      if (useNewZNodePath) {
        accountService.setupRouter(router);
      }
      return accountService;
    } catch (Exception e) {
      throw new IllegalStateException("Could not instantiate HelixAccountService", e);
    }
  }
Constructor.
@param verifiableProperties The properties to start a {@link HelixAccountService}.
@param notifier The {@link Notifier} to start a {@link HelixAccountService}.
@param metricRegistry The {@link MetricRegistry} to start a {@link HelixAccountService}.
@param router The {@link Router} to add to {@link HelixAccountService}
ambry-account/src/test/java/com/github/ambry/account/MockHelixAccountServiceFactory.java