public void CanCrudConsent()
        {
            // can register
            IConsent consent = ConsentService.RegisterConsent("user/1234", "app1", "do-something", ConsentState.Granted, "no comment");

            Assert.AreNotEqual(0, consent.Id);

            Assert.IsTrue(consent.Current);
            Assert.AreEqual("user/1234", consent.Source);
            Assert.AreEqual("app1", consent.Context);
            Assert.AreEqual("do-something", consent.Action);
            Assert.AreEqual(ConsentState.Granted, consent.State);
            Assert.AreEqual("no comment", consent.Comment);

            Assert.IsTrue(consent.IsGranted());

            // can register more
            ConsentService.RegisterConsent("user/1234", "app1", "do-something-else", ConsentState.Granted, "no comment");
            ConsentService.RegisterConsent("user/1236", "app1", "do-something", ConsentState.Granted, "no comment");
            ConsentService.RegisterConsent("user/1237", "app2", "do-something", ConsentState.Granted, "no comment");

            // can get by source
            IConsent[] consents = ConsentService.LookupConsent(source: "user/1235").ToArray();
            Assert.IsEmpty(consents);

            consents = ConsentService.LookupConsent(source: "user/1234").ToArray();
            Assert.AreEqual(2, consents.Length);
            Assert.IsTrue(consents.All(x => x.Source == "user/1234"));
            Assert.IsTrue(consents.Any(x => x.Action == "do-something"));
            Assert.IsTrue(consents.Any(x => x.Action == "do-something-else"));

            // can get by context
            consents = ConsentService.LookupConsent(context: "app3").ToArray();
            Assert.IsEmpty(consents);

            consents = ConsentService.LookupConsent(context: "app2").ToArray();
            Assert.AreEqual(1, consents.Length);

            consents = ConsentService.LookupConsent(context: "app1").ToArray();
            Assert.AreEqual(3, consents.Length);
            Assert.IsTrue(consents.Any(x => x.Action == "do-something"));
            Assert.IsTrue(consents.Any(x => x.Action == "do-something-else"));

            // can get by action
            consents = ConsentService.LookupConsent(action: "do-whatever").ToArray();
            Assert.IsEmpty(consents);

            consents = ConsentService.LookupConsent(context: "app1", action: "do-something").ToArray();
            Assert.AreEqual(2, consents.Length);
            Assert.IsTrue(consents.All(x => x.Action == "do-something"));
            Assert.IsTrue(consents.Any(x => x.Source == "user/1234"));
            Assert.IsTrue(consents.Any(x => x.Source == "user/1236"));

            // can revoke
            consent = ConsentService.RegisterConsent("user/1234", "app1", "do-something", ConsentState.Revoked, "no comment");

            consents = ConsentService.LookupConsent(source: "user/1234", context: "app1", action: "do-something").ToArray();
            Assert.AreEqual(1, consents.Length);
            Assert.IsTrue(consents[0].Current);
            Assert.AreEqual(ConsentState.Revoked, consents[0].State);

            // can filter
            consents = ConsentService.LookupConsent(context: "app1", action: "do-", actionStartsWith: true).ToArray();
            Assert.AreEqual(3, consents.Length);
            Assert.IsTrue(consents.All(x => x.Context == "app1"));
            Assert.IsTrue(consents.All(x => x.Action.StartsWith("do-")));

            // can get history
            consents = ConsentService.LookupConsent(source: "user/1234", context: "app1", action: "do-something", includeHistory: true).ToArray();
            Assert.AreEqual(1, consents.Length);
            Assert.IsTrue(consents[0].Current);
            Assert.AreEqual(ConsentState.Revoked, consents[0].State);
            Assert.IsTrue(consents[0].IsRevoked());
            Assert.IsNotNull(consents[0].History);
            IConsent[] history = consents[0].History.ToArray();
            Assert.AreEqual(1, history.Length);
            Assert.IsFalse(history[0].Current);
            Assert.AreEqual(ConsentState.Granted, history[0].State);

            // cannot be stupid
            Assert.Throws <ArgumentException>(() =>
                                              ConsentService.RegisterConsent("user/1234", "app1", "do-something", ConsentState.Granted | ConsentState.Revoked, "no comment"));
        }