public void SuccessMatch()
        {
            // Arrange
            var validatorFactory = new Mock<IValidatorEngine>();
            var mappingEngine = new Mock<IMappingEngine>();
            var repository = new Mock<IRepository>();
            var searchCache = new Mock<ISearchCache>();
            var service = new CounterpartyService(validatorFactory.Object, mappingEngine.Object, repository.Object, searchCache.Object);

            // Domain details
            var system = new MDM.SourceSystem { Name = "Endur" };
            var mapping = new PartyRoleMapping
                {
                    System = system,
                    MappingValue = "A"
                };
            var targetSystem = new MDM.SourceSystem { Name = "Trayport" };
            var targetMapping = new PartyRoleMapping
                {
                    System = targetSystem,
                    MappingValue = "B",
                    IsDefault = true
                };
            var details = new MDM.CounterpartyDetails
                {
                    Name = "Test",
                };
            var counterparty = new MDM.Counterparty
                {
                    Id = 1
                };
            counterparty.AddDetails(details);
            counterparty.ProcessMapping(mapping);
            counterparty.ProcessMapping(targetMapping);

            // Contract details
            var targetIdentifier = new MdmId
                {
                    SystemName = "Trayport",
                    Identifier = "B"
                };

            mappingEngine.Setup(x => x.Map<PartyRoleMapping, MdmId>(targetMapping)).Returns(targetIdentifier);

            var list = new List<PartyRoleMapping> { mapping };
            repository.Setup(x => x.Queryable<PartyRoleMapping>()).Returns(list.AsQueryable());

            var request = new CrossMappingRequest
            {
                SystemName = "Endur",
                Identifier = "A",
                TargetSystemName = "trayport",
                ValidAt = SystemTime.UtcNow(),
                Version = 1
            };

            // Act
            var response = service.CrossMap(request);
            var candidate = response.Contract;

            // Assert
            Assert.IsNotNull(response, "Contract null");
            Assert.IsTrue(response.IsValid, "Contract invalid");
            Assert.IsNotNull(candidate, "Mapping null");
            Assert.AreEqual(1, candidate.Mappings.Count, "Identifier count incorrect");
            Assert.AreSame(targetIdentifier, candidate.Mappings[0], "Different identifier assigned");
        }