@Test
  public void testReadConflictAccountDataFromHelixPropertyStoreCase3() throws Exception {
    Account account1 = new AccountBuilder((short) 1, "a", AccountStatus.INACTIVE).build();
    List<Account> accounts = Collections.singletonList(account1);
    writeAccountsToHelixPropertyStore(accounts, false);
    accountService = mockHelixAccountServiceFactory.getAccountService();
    assertAccountInAccountService(account1, accountService);

    Account account2 = new AccountBuilder((short) 2, "b", AccountStatus.INACTIVE).build();
    accounts = Collections.singletonList(account2);
    writeAccountsToHelixPropertyStore(accounts, false);

    Account conflictingAccount = new AccountBuilder((short) 3, "b", AccountStatus.INACTIVE).build();
    accounts = Collections.singletonList(conflictingAccount);
    assertUpdateAccountsFails(accounts, AccountServiceErrorCode.InternalError, accountService);
    assertEquals("Number of account is wrong.", 1, accountService.getAllAccounts().size());
    assertAccountInAccountService(account1, accountService);
  }
Tests a series of operations.
1. PrePopulates account (1, "a");
2. Starts up a {@link HelixAccountService};
3. Remote copy adds a new account (2, "b"), and the update has not been propagated to the {@link HelixAccountService};
4. The {@link HelixAccountService} attempts to update an account (3, "b"), which should fail because it will eventually
   conflict with the remote copy;
@throws Exception Any unexpected exception.
ambry-account/src/test/java/com/github/ambry/account/HelixAccountServiceTest.java