public KnowledgeGroupViewModel(
     IRepositoryFactory <ICustomerRepository> repositoryFactory,
     IViewModelsFactory <IKnowledgeGroupViewModel> groupVmFactory,
     ICustomerRepository customerRepository,
     ICustomerEntityFactory entityFactory,
     KnowledgeBaseGroup item)
     : base(null, null)
 {
     _repositoryFactory          = repositoryFactory;
     _groupVmFactory             = groupVmFactory;
     CustomersRepository         = customerRepository;
     _originalItem               = item;
     InnerItem                   = _originalItem.DeepClone(entityFactory as IKnownSerializationTypes);
     _innerItem.PropertyChanged += _innerItem_PropertyChanged;
     EmbeddedHierarchyEntry      = this;
 }