@Test
  public void receiveBadTopic() throws Exception {
    accountService = mockHelixAccountServiceFactory.getAccountService();
    updateAccountsAndAssertAccountExistence(idToRefAccountMap.values(), NUM_REF_ACCOUNT, true);
    notifier.publish("badTopic", FULL_ACCOUNT_METADATA_CHANGE_MESSAGE);
    assertEquals("The number of account in HelixAccountService is different from expected", NUM_REF_ACCOUNT,
        accountService.getAllAccounts().size());
  }
Tests receiving a bad topic, it will not be recognized by {@link HelixAccountService}, but will also not
crash the service.
@throws Exception Any unexpected exception.
ambry-account/src/test/java/com/github/ambry/account/HelixAccountServiceTest.java