public void ReturnNullForNullEntityIdIdentifier()
        {
            var entityId = new EntityId();

            var candidate = entityId.MdmId();
            Assert.IsFalse(candidate.HasValue);
        }
        public void ReturnsZeroForNonNumericIdentifierValue()
        {
            var entityId = new EntityId { Identifier = new MdmId { Identifier = "A" } };

            var candidate = entityId.MdmId();
            Assert.IsTrue(candidate.HasValue);
            Assert.AreEqual(0, candidate.Value);
        }