def test_multiply_numbers_with_real_and_imaginary_part(self):
first_input = ComplexNumber(1, 2)
second_input = ComplexNumber(3, 4)
self.assertEqual(first_input.mul(second_input).real, -5)
self.assertEqual(first_input.mul(second_input).imaginary, 10)
def test_multiply_purely_imaginary_numbers(self):
first_input = ComplexNumber(0, 1)
second_input = ComplexNumber(0, 2)
self.assertEqual(first_input.mul(second_input).real, -2)
self.assertEqual(first_input.mul(second_input).imaginary, 0)
