private void PreviousNavCommandHandler()
        {
            RoleListView.MoveCurrentToPrevious();

            if (RoleListView.IsCurrentBeforeFirst == true)
            {
                RoleListView.MoveCurrentToFirst();
            }

            SelectedRole = (RoleModel)RoleListView.CurrentItem;
        }
        private void FirstNavCommandHandler()
        {
            RoleListView.MoveCurrentToFirst();

            SelectedRole = (RoleModel)RoleListView.CurrentItem;
        }