@Override
  public synchronized void deleteDatasetVersion(String accountName, String containerName,
      String datasetName, String version) throws AccountServiceException {
    Account account = nameToAccountMap.get(accountName);
    short accountId = account.getId();
    short containerId = account.getContainerByName(containerName).getId();
    idToDatasetVersionMap.get(new Pair<>(accountId, containerId)).remove(new Pair<>(datasetName, version));
  }
Constructor.
@param shouldReturnOnlyUnknown {@code true} if always returns {@link InMemAccountService#UNKNOWN_ACCOUNT} when queried
                                                    by account name; {@code false} to do the actual query.
@param notifyConsumers {@code true} if consumers should be notified of account changes. {@code false} otherwise.
ambry-test-utils/src/main/java/com/github/ambry/account/InMemAccountService.java