def test_mixedOffersAreSumOfSpecialAndIndividualPrices(self):
    self.assertEqual(checkout('AAAAAAA'), (checkout('AAAAA') + checkout('AA')))
    self.assertEqual(checkout('BBB'), (checkout('BB') + checkout('B')))
def test_mixedOffersAreSumOfSpecialAndIndividualPrices(self):
    self.assertEqual(checkout('AAAAAAA'), (checkout('AAAAA') + checkout('AA')))
    self.assertEqual(checkout('BBB'), (checkout('BB') + checkout('B')))