class TestCalculator1(unittest.TestCase):
    def setUp(self):
		self.calc = Calculator()

	#  test add function
	#
    def test_calculator_add_method_returns_correct_result(self):
		self.assertEqual(4, self.calc.add1(2, 2))
		self.assertEqual(0, self.calc.add1(-5, 5))
		self.assertEqual(-8, self.calc.add1(-4,-4))

    def test_calculator_add_method_returns_error_result(self):
		self.assertEqual(5, self.calc.add1(2, 2))

    def test_calculator_add_method_returns_nunnumer_error_result(self):
		self.assertEqual(4, self.calc.add1("two", 2))