FluentNHibernate.MappingModel.ClassBased.ClassMapping.AddJoin C# (CSharp) Method

        public void AddJoin(JoinMapping join)
        {
            joins.Add(join);
        }

        public void ShouldWriteTheJoins()
        {
            var classMapping = new ClassMapping();
            classMapping.AddJoin(new JoinMapping());

            var joinDocument = new XmlDocument();
            joinDocument.AppendChild(joinDocument.CreateElement("join"));

            var joinWriter = MockRepository.GenerateMock<IXmlWriter<JoinMapping>>();
            joinWriter
                .Expect(x => x.Write(classMapping.Joins.First()))
                .Return(joinDocument);

            XmlClassWriter writer = new XmlClassWriter(null, null, null, null, null, joinWriter);

            writer.VerifyXml(classMapping)
                .Element("join").Exists();
        }