static Pair<Account, Container> getAccountContainer(AccountService accountService, short accountId,
      short containerId) {
    Account account = accountService.getAccountById(accountId);
    Container container = account == null ? null : account.getContainerById(containerId);
    return new Pair<>(account, container);
  }
Return {@link Account} and {@link Container} in a {@link Pair}.
@param accountService the accountService to translate accountId to name.
@param accountId the accountId to translate.
@return {@link Account} and {@link Container} in a {@link Pair}.
ambry-router/src/main/java/com/github/ambry/router/RouterUtils.java