private Func <Order, bool> WhenDeleteAdultOrder()
        {
            Func <Order, bool> modelDeletePredicate = null;

            _model.When(m => m.Delete(Arg.Any <Func <Order, bool> >()))
            .Do(m => modelDeletePredicate = m[0] as Func <Order, bool>);

            _orderController.DeleteAdultOrders();
            return(modelDeletePredicate);
        }