@Test
  public void testDisableBackgroundUpdater() {
    helixConfigProps.setProperty(HelixAccountServiceConfig.UPDATER_POLLING_INTERVAL_MS_KEY, "0");
    vHelixConfigProps = new VerifiableProperties(helixConfigProps);
    storeConfig = new HelixPropertyStoreConfig(vHelixConfigProps);
    String updaterThreadPrefix = UUID.randomUUID().toString();
    MockHelixAccountServiceFactory mockHelixAccountServiceFactory =
        new MockHelixAccountServiceFactory(vHelixConfigProps, new MetricRegistry(), notifier, updaterThreadPrefix,
            mockRouter);
    accountService = mockHelixAccountServiceFactory.getAccountService();
    assertEquals("Wrong number of thread for account updater.", 0, numThreadsByThisName(updaterThreadPrefix));
  }
Tests disabling the background thread. By setting the polling interval to 0ms, the accounts should not be fetched.
Therefore, after the {@link HelixAccountService} starts, there should be a single get call to the
{@link HelixPropertyStore}.
ambry-account/src/test/java/com/github/ambry/account/HelixAccountServiceTest.java