public void AddTokenTest()
        {
            var           key   = new Uri("http://www.tokencache.com/");
            SecurityToken token = new SamlSecurityToken(new SamlAssertion());

            TokenCacheHelper.AddToken(key, token);
            var t = TokenCacheHelper.GetToken(key);

            Assert.AreEqual(token, t);

            TokenCacheHelper.AddToken(key, token);
            t = TokenCacheHelper.GetToken(key);
            Assert.AreEqual(token, t);
        }