protected override void Edit()
        {
            RoleDetailViewModel detailModelView = new RoleDetailViewModel(SelectedItem, false);

            if (NavigationService.NavigateTo("Detail", detailModelView) == NavigationResult.Ok)
            {
                ParentObject.MarkChildForUpdate(SelectedItem);
            }
        }
        protected override void New()
        {
            RoleDTO             newRole         = new RoleDTO();
            RoleDetailViewModel detailModelView = new RoleDetailViewModel(newRole, true);

            if (NavigationService.NavigateTo("Detail", detailModelView) == NavigationResult.Ok)
            {
                newRole = detailModelView.Model;
                ParentObject.MarkChildForInsertion(newRole);
                Items.Add(newRole);
                SelectedItem = newRole;
            }
        }