@Override
  protected void deleteEntity(PersistentEntity pe, Object obj) {
    EntityAccess entityAccess = createEntityAccess(pe, obj);
    if (cancelDelete(pe, entityAccess)) {
      return;
    }

    for (Association association : pe.getAssociations()) {
      if (association.isOwningSide() && association.doesCascade(CascadeType.REMOVE)) {
        log.debug("cascading delete for property " + association.getName());

        GraphPersistentEntity otherPersistentEntity =
            (GraphPersistentEntity) association.getAssociatedEntity();
        Object otherSideValue = entityAccess.getProperty(association.getName());
        if (association instanceof ToOne) {
          deleteEntity(otherPersistentEntity, otherSideValue);
        } else {
          deleteEntities(otherPersistentEntity, (Iterable) otherSideValue);
        }
      }
    }

    getCypherEngine()
        .execute(
            String.format(
                "MATCH (n:%s) WHERE n.__id__={id} OPTIONAL MATCH (n)-[r]-() DELETE r,n",
                ((GraphPersistentEntity) pe).getLabel()),
            Collections.singletonMap("id", entityAccess.getIdentifier()));

    firePostDeleteEvent(pe, entityAccess);
  }
  private Object unmarshall(PersistentEntity persistentEntity, Long id, Map<String, Object> data) {

    log.debug("unmarshalling entity {}, props {}, {}", id, data);
    EntityAccess entityAccess = new EntityAccess(persistentEntity, persistentEntity.newInstance());
    entityAccess.setConversionService(persistentEntity.getMappingContext().getConversionService());
    entityAccess.setIdentifier(id);
    data.remove("__id__");

    for (PersistentProperty property :
        entityAccess.getPersistentEntity().getPersistentProperties()) {

      String propertyName = property.getName();
      if (property instanceof Simple) { // implicitly sets version property as well
        entityAccess.setProperty(propertyName, data.remove(propertyName));
        //            } else if (property instanceof OneToOne) {
        //                log.error("property " + property.getName() + " is of type " +
        // property.getClass().getSuperclass());
      } else if (property instanceof ToOne) {
        ToOne to = (ToOne) property;

        CypherResult cypherResult =
            getSession()
                .getNativeInterface()
                .execute(
                    CypherBuilder.findRelationshipEndpointIdsFor(to),
                    Collections.singletonMap("id", id));

        Map<String, Object> row = IteratorUtil.singleOrNull(cypherResult);
        if (row != null) {
          Long endpointId = (Long) row.get("id");
          entityAccess.setProperty(
              propertyName,
              getMappingContext()
                  .getProxyFactory()
                  .createProxy(session, to.getAssociatedEntity().getJavaClass(), endpointId));
        }
      } else if ((property instanceof OneToMany) || (property instanceof ManyToMany)) {

        LazyEnititySet lazyEnititySet =
            new LazyEnititySet(
                entityAccess,
                (Association) property,
                getMappingContext().getProxyFactory(),
                getSession());
        entityAccess.setProperty(propertyName, lazyEnititySet);

      } else {
        throw new IllegalArgumentException(
            "property $property.name is of type ${property.class.superclass}");
      }
    }

    if (!data.isEmpty()) {
      GroovyObject go = (GroovyObject) (entityAccess.getEntity());
      go.setProperty(Neo4jGormEnhancer.UNDECLARED_PROPERTIES, data);
    }

    firePostLoadEvent(entityAccess.getPersistentEntity(), entityAccess);
    return entityAccess.getEntity();
  }
  @Override
  protected void deleteEntities(
      PersistentEntity pe, @SuppressWarnings("rawtypes") Iterable objects) {
    List<EntityAccess> entityAccesses = new ArrayList<EntityAccess>();
    List<Object> ids = new ArrayList<Object>();
    Map<PersistentEntity, Collection<Object>> cascades =
        new HashMap<PersistentEntity, Collection<Object>>();

    for (Object obj : objects) {
      EntityAccess entityAccess = createEntityAccess(pe, obj);
      if (cancelDelete(pe, entityAccess)) {
        return;
      }
      entityAccesses.add(entityAccess);
      ids.add(entityAccess.getIdentifier());

      // populate cascades
      for (Association association : pe.getAssociations()) {
        Object property = entityAccess.getProperty(association.getName());
        if (association.isOwningSide()
            && association.doesCascade(CascadeType.REMOVE)
            && (property != null)) {

          PersistentEntity associatedEntity = association.getAssociatedEntity();

          Collection<Object> cascadesForPersistentEntity = cascades.get(associatedEntity);
          if (cascadesForPersistentEntity == null) {
            cascadesForPersistentEntity = new ArrayList<Object>();
            cascades.put(associatedEntity, cascadesForPersistentEntity);
          }

          if (association instanceof ToOne) {
            cascadesForPersistentEntity.add(property);
          } else {
            cascadesForPersistentEntity.addAll((Collection<?>) property);
          }
        }
      }
    }

    for (Map.Entry<PersistentEntity, Collection<Object>> entry : cascades.entrySet()) {
      deleteEntities(entry.getKey(), entry.getValue());
    }

    getCypherEngine()
        .execute(
            String.format(
                "MATCH (n:%s) WHERE n.__id__ in {ids} OPTIONAL MATCH (n)-[r]-() DELETE r,n",
                ((GraphPersistentEntity) pe).getLabel()),
            Collections.singletonMap("ids", ids));

    for (EntityAccess entityAccess : entityAccesses) {
      firePostDeleteEvent(pe, entityAccess);
    }
  }