'This tests that the generate_receipt_instructions call chain and also
that calling it on the base OrderItem class returns an empty list'

def test_order_item_generate_receipt_instructions(self):

    cart = Order.get_cart_for_user(self.user)
    item = OrderItem(user=self.user, order=cart)
    item.save()
    self.assertTrue(cart.has_items())
    (inst_dict, inst_set) = cart.generate_receipt_instructions()
    self.assertDictEqual({item.pk_with_subclass: set([])}, inst_dict)
    self.assertEquals(set([]), inst_set)
