@Override
  public void updateAccounts(Collection<Account> accounts) throws AccountServiceException {
    updateAccountsWithAccountMetadataStore(accounts, accountMetadataStore);
  }
{@inheritDoc}
<p>
  This call is blocking until it completes the operation of updating account metadata to {@link HelixPropertyStore}.
</p>
<p>
  There is a slight chance that an {@link Account} could be updated successfully, but its value was
  set based on an outdated {@link Account}. This can be fixed after {@code generationId} is introduced
  to {@link Account}.
</p>
ambry-account/src/main/java/com/github/ambry/account/HelixAccountService.java