def test_hourly_rent(self):
shop = BikeRental(10)
hour = datetime.now().hour
self.assertEqual(shop.rentBikeOnHour(2).hour, hour, 'no assertion')
def test_negative_number_of_bikes(self):
shop = BikeRental(10)
self.assertEqual(shop.rentBikeOnHour(-3), None, 'should be None')
self.assertEqual(shop.rentBikeOnHour(0), None, 'should be None')