public class ClassMapTester
    {
        protected XmlElement currentElement;
        protected XmlDocument document;
        protected XmlNamespaceManager mgr;


        public ClassMapTester ForString(string input)
        {
            document = new XmlDocument();
            document.LoadXml(input);
            return For(document);
        }

        public ClassMapTester For(XmlDocument doc)
        {
            document = doc;
            SetNameSpaceManager();
            return this;
        }

        public ClassMapTester For() where A : ClassMap, new()
        {
            For(new A().CreateMapping(new MappingVisitor()));
            return this;
        }

        private void SetNameSpaceManager()
        {
            mgr = new XmlNamespaceManager(new NameTable());
            mgr.AddNamespace("urn", "urn:nhibernate-mapping-2.2");
        }

        //....
     }

[Test]
public void LanguageMap_Creates_Valid_Mapping()
{
    new ClassMapTester().For()
        .TestDefaultConventions()
        .TestProperty("LanguageName", "8", "true").Exists()
        .TestProperty("LanguageDisplayName", "50", "true").Exists();
}