public void op_Compare_BritishPostcode_BritishPostcode_whenSame()
        {
            BritishPostcode obj = "GU21 4XG";

            const int expected = 0;
            var       actual   = BritishPostcode.Compare(obj, obj);

            Assert.Equal(expected, actual);
        }
        public void op_Compare_BritishPostcode_BritishPostcode(int expected,
                                                               string comparand1,
                                                               string comparand2)
        {
            BritishPostcode postcode1 = comparand1;
            BritishPostcode postcode2 = comparand2;

            var actual = BritishPostcode.Compare(postcode1, postcode2);

            Assert.Equal(expected, actual);
        }