def test_getAndSetNonPrimitiveProperties():
calc = Calculator()
calc.add(3_200_000)
calc.neg()
calc.curr = Multiply(Number(2), calc.curr)
assert calc.value == -6_400_000
def test_subclassing():
calc = Calculator()
calc.curr = AddTen(33)
calc.neg()
assert calc.value == -43