@Override
  public PortfolioDocument update(PortfolioDocument document) {
    ArgumentChecker.notNull(document, "document");
    ArgumentChecker.notNull(document.getUniqueId(), "document.uniqueId");
    ArgumentChecker.notNull(document.getPortfolio(), "document.portfolio");

    final UniqueId uniqueId = document.getUniqueId();
    final Instant now = Instant.now();
    final PortfolioDocument storedDocument = _store.get(uniqueId.getObjectId());
    if (storedDocument == null) {
      throw new DataNotFoundException("Portfolio not found: " + uniqueId);
    }

    final PortfolioDocument clonedDoc = clonePortfolioDocument(document);
    removeNodes(storedDocument.getPortfolio().getRootNode());

    setVersionTimes(document, clonedDoc, now, null, now, null);

    if (_store.replace(uniqueId.getObjectId(), storedDocument, clonedDoc) == false) {
      throw new IllegalArgumentException("Concurrent modification");
    }
    storeNodes(
        clonedDoc.getPortfolio().getRootNode(),
        document.getPortfolio().getRootNode(),
        uniqueId,
        null);
    _changeManager.entityChanged(
        ChangeType.CHANGED,
        document.getObjectId(),
        document.getVersionFromInstant(),
        document.getVersionToInstant(),
        now);
    updateCaches(storedDocument, clonedDoc);
    return document;
  }
  @Override
  public PortfolioDocument add(PortfolioDocument document) {
    ArgumentChecker.notNull(document, "document");
    ArgumentChecker.notNull(document.getPortfolio(), "document.portfolio");

    final ObjectId objectId = _objectIdSupplier.get();
    final UniqueId uniqueId = objectId.atVersion("");
    final Instant now = Instant.now();

    final PortfolioDocument clonedDoc = clonePortfolioDocument(document);
    setDocumentId(document, clonedDoc, uniqueId);
    setVersionTimes(document, clonedDoc, now, null, now, null);
    _store.put(objectId, clonedDoc);
    storeNodes(
        clonedDoc.getPortfolio().getRootNode(),
        document.getPortfolio().getRootNode(),
        uniqueId,
        null);
    _changeManager.entityChanged(
        ChangeType.ADDED,
        objectId,
        document.getVersionFromInstant(),
        document.getVersionToInstant(),
        now);
    updateCaches(null, clonedDoc);
    return document;
  }