def test_exceptions():
calc3 = Calculator(initial_value=20, maximum_value=30)
calc3.add(3)
assert calc3.value == 23
with pytest.raises(Exception):
calc3.add(10)
calc3.max_value = 40
calc3.add(10)
assert calc3.value == 33
def test_undefinedAndNull():
calc = Calculator()
assert calc.max_value is None
calc.max_value = None