def test_multi(self):
        a = Spinner.xor(    bytearray([int('0b10101010', 2), int('0b10010110', 2)]),
                            bytearray([int('0b00000000', 2), int('0b11111111', 2)]))
        self.assertEqual(a, bytearray([int('0b10101010', 2), int('0b01101001', 2)]))

        a = Spinner.xor(    bytearray([int('0b10101010', 2), int('0b10010110', 2)]),
                            bytearray([int('0b11111111', 2), int('0b00000000', 2)]))
        self.assertEqual(a, bytearray([int('0b01010101', 2), int('0b10010110', 2)]))
    def test_simple(self):
        a = Spinner.xor(bytearray([int('0b00000000', 2)]),
                        bytearray([int('0b00000000', 2)]))
        self.assertEqual(a[0],     int('0b00000000', 2))

        a = Spinner.xor(bytearray([int('0b00000000', 2)]),
                        bytearray([int('0b00000001', 2)]))
        self.assertEqual(a[0],     int('0b00000001', 2))

        a = Spinner.xor(bytearray([int('0b00000001', 2)]),
                        bytearray([int('0b00000000', 2)]))
        self.assertEqual(a[0],     int('0b00000001', 2))

        a = Spinner.xor(bytearray([int('0b00000001', 2)]),
                        bytearray([int('0b00000001', 2)]))
        self.assertEqual(a[0],     int('0b00000000', 2))