public void TestGuidToHex()
        {
            Guid   guid = Guid.Parse("ef27b4b9-f6e9-46f5-ab2b-47bbb24746c5");
            string hex  = JaegerWavefrontPropagator.GuidToHex(guid);

            Assert.Equal("ef27b4b9f6e946f5ab2b47bbb24746c5", hex);
        }
        public void TestHexToGuid()
        {
            string hex  = "ef27b4b9f6e946f5ab2b47bbb24746c5";
            Guid?  guid = JaegerWavefrontPropagator.HexToGuid(hex);

            Assert.Equal("ef27b4b9-f6e9-46f5-ab2b-47bbb24746c5",
                         guid.HasValue ? guid.Value.ToString() : null);
        }