@Test
  public void testNonConflictingUpdateCaseC() throws Exception {
    accountService = mockHelixAccountServiceFactory.getAccountService();
    // write two accounts (1, "a") and (2, "b")
    writeAccountsForConflictTest();
    Collection<Account> nonConflictAccounts =
        Collections.singleton((new AccountBuilder((short) 3, "c", AccountStatus.ACTIVE).build()));
    updateAccountsAndAssertAccountExistence(nonConflictAccounts, 3, true);
  }
Tests updating a {@link Account}, which has a new id and name different from any of the existing record. The
new record will replace the existing record. This test corresponds to case C specified in the JavaDoc of
{@link AccountService}.
@throws Exception Any unexpected exception.
ambry-account/src/test/java/com/github/ambry/account/HelixAccountServiceTest.java