public void GetAllXamlNamespaces()
        {
            var ctx = new XamlSchemaContext(null, null);
            var arr = ctx.GetAllXamlNamespaces().ToArray();

            Assert.AreEqual(6, arr.Length, "#1");
            Assert.IsTrue(arr.Contains(XamlLanguage.Xaml2006Namespace), "#1-2");
            Assert.IsTrue(arr.Contains("urn:mono-test"), "#1-3");
            Assert.IsTrue(arr.Contains("urn:mono-test2"), "#1-4");
            Assert.IsTrue(arr.Contains("urn:bar"), "#1-5");

            ctx = NewStandardContext();
            arr = ctx.GetAllXamlNamespaces().ToArray();
            Assert.AreEqual(1, arr.Length, "#2");
            Assert.AreEqual(XamlLanguage.Xaml2006Namespace, arr [0], "#2-2");

            ctx = NewThisAssemblyContext();
            arr = ctx.GetAllXamlNamespaces().ToArray();
            Assert.AreEqual(5, arr.Length, "#3");
            Assert.IsTrue(arr.Contains("urn:mono-test"), "#3-2");
            Assert.IsTrue(arr.Contains("urn:mono-test2"), "#3-3");
            Assert.IsTrue(arr.Contains("urn:bar"), "#3-4");
        }