public void IDictionaryTests()
        {
            string n0  = "user type";
            var    t   = new UserTypes();
            var    ut0 = new UserType(n0, typeof(string), null);

            t.Add(n0, ut0);
            Assert.Single(t);
            Assert.Equal(ut0, t[n0]);
            Assert.True(t.ContainsKey(n0));
            Assert.True(t.Remove(n0));
            Assert.Empty(t);
        }