public void NullIdConvertsToEmpty()
        {
            XAttribute attr = null;
            var        guid = attr.ConvertToGuid();

            Assert.That(guid, Is.EqualTo(Guid.Empty));
        }
        public void CanConvertIdToGuid()
        {
            var attr = new XAttribute("id", "10");
            var guid = attr.ConvertToGuid();

            Assert.That(guid, Is.Not.EqualTo(Guid.Empty));
        }