public void ReturnNullForZeroIdentifiers()
        {
            var entity = new SourceSystem();

            var candidate = entity.ToMdmKeyString();

            Assert.IsNull(candidate);
        }
        public void ReturnNullForNoNexusIdentifier()
        {
            var entity = new SourceSystem();
            entity.Identifiers.Add(new MdmId());

            var candidate = entity.ToMdmKeyString();

            Assert.IsNull(candidate);
        }
        public void ReturnNexusIdentifier()
        {
            var expected = new MdmId { Identifier = "1", IsMdmId = true };
            var entity = new SourceSystem { Identifiers = new MdmIdList { new MdmId(), expected } };

            var candidate = entity.ToMdmKeyString();

            Assert.AreEqual("1", candidate);
        }