def test_instantiation_with_zero_as_default_calculation():
    # ARRANGE #
    calc = Calculator()

    # ACT #
    actual = calc.get_last_calculation()
    expected = 0

    # ASSERT #
    assert actual == expected
def test_instantiation_with_initial_calculation():
    # ARRANGE #
    calc = Calculator(1 + 1)

    # ACT #
    actual = calc.get_last_calculation()
    expected = 2

    # ASSERT #
    assert actual == expected