@Test
  public void testCreateAccount() throws Exception {
    assertEquals("Wrong number of accounts", 0, accountService.getAllAccounts().size());
    createOrUpdateAccountsAndWait(idToRefAccountMap.values());
    assertAccountsInAccountService(idToRefAccountMap.values(), NUM_REF_ACCOUNT, accountService);
  }
Tests creating {@link Account}s to {@code ZooKeeper}, where no {@link Account} exists.
@throws Exception Any unexpected exception.
ambry-tools/src/integration-test/java/com/github/ambry/account/AccountUpdateToolTest.java