public void TestRemoveOntology()
 {
     Dictionary<string, OntologyAttribute> dict = CreateRealisticNamespaceDictionary();
     nsm = new NamespaceManager(dict);
     Assert.IsTrue(nsm.Count == 4);
     nsm.Remove("Name3");
     Assert.IsTrue(nsm.Count == 3);
     Assert.IsNull(nsm["Name3"]);
 }