def test_cars_sale_price():
    v1 = Car(maker='Ford', model='Mustang', year=2005,
             base_price=18000, miles=31000)
    v2 = Car(maker='Ford', model='Mustang', year=2014,
             base_price=31000, miles=11000)

    assert v1.sale_price() == 21600
    assert v2.sale_price() == 37200
    def test_cars_sale_price(self):
        v1 = Car(maker='Ford',
                 model='Mustang',
                 year=2005,
                 base_price=18000,
                 miles=31000)
        v2 = Car(maker='Ford',
                 model='Mustang',
                 year=2014,
                 base_price=31000,
                 miles=11000)

        self.assertEqual(v1.sale_price(), 21600)
        self.assertEqual(v2.sale_price(), 37200)