public StoreCategoryViewModel(TreeViewModelBase parent, StoreCategoryInfo model)
            : base(parent)
        {
            this.Model = model;

            this.Name                = model.ToReactivePropertyAsSynchronized(n => n.Name).AddTo(_disposable);
            this.IsSelected          = new ReactiveProperty <bool>().AddTo(_disposable);
            this.IsExpanded          = model.ToReactivePropertyAsSynchronized(n => n.IsExpanded).AddTo(_disposable);
            this.SignatureViewModels = model.SignatureInfos.ToReadOnlyReactiveCollection(n => new StoreSignatureViewModel(this, n)).AddTo(_disposable);
            this.CategoryViewModels  = model.CategoryInfos.ToReadOnlyReactiveCollection(n => new StoreCategoryViewModel(this, n)).AddTo(_disposable);
        }