def test_undefined(self):
        """
        The pairs of values 0 and 128, 1 and 129, 2 and 130, etc, to 127 and 255
        are not equal, but in each pair, neither number is defined as being
        greater than, or less than, the other.
        """
        assertUndefinedComparison(self, serialNumber8(0), serialNumber8(128))
        assertUndefinedComparison(self, serialNumber8(1), serialNumber8(129))
        assertUndefinedComparison(self, serialNumber8(2), serialNumber8(130))
        assertUndefinedComparison(self, serialNumber8(127), serialNumber8(255))

        The pairs of values 0 and 128, 1 and 129, 2 and 130, etc, to 127 and 255
        are not equal, but in each pair, neither number is defined as being
        greater than, or less than, the other.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_rfc1982.py