def test_calculator_return_difference(self):
calculator = Calculator()
result = calculator.difference(1, 2)
self.assertEqual(-1, result)
def test_calculator_access_difference_result(self):
calculator = Calculator()
calculator.difference(1, 2)
self.assertEqual(-1, calculator.Result)
def test_multiple_calculators(self):
calculator1 = Calculator()
calculator2 = Calculator()
calculator3 = Calculator()
calculator3.sum(calculator1.sum(1, 2), calculator2.difference(3, 4))
self.assertEqual(2, calculator3.Result)
