public void TestInterception()
        {
            List <ExceptionNotification> Received = new List <ExceptionNotification>();
            var src = new TestSource
            {
                ExceptionHandler = (o, a) => Received.Add(a)
            };

            src.Test("Unintercepted");
            Assert.AreEqual(1, Received.Count());
            Assert.IsTrue(Received.All(r => r.Message == "Unintercepted"));

            string intercepted = null;

            using (src.Catch((_, args) => intercepted = args.Message))
            {
                src.Test("Intercepted-true");
            }

            Assert.AreEqual("Intercepted-true", intercepted);
            Assert.AreEqual(1, Received.Count());   // since we've intercepted
            Assert.IsFalse(Received.Any(r => r.Message == "Intercepted-true"));

            src.Test("Unintercepted2");

            Assert.AreEqual("Intercepted-true", intercepted); // should not have intercepted anymore
            Assert.AreEqual(2, Received.Count());             // original sink remains active
            Assert.AreEqual("Unintercepted2", Received.Last().Message);
        }
        public void TestInterceptionWhenNoSink()
        {
            var src = new TestSource
            {
                ExceptionHandler = null   // that's the point
            };

            string intercepted = null;

            using (src.Catch((_, args) => intercepted = args.Message))
            {
                src.Test("Intercepted-true");
            }

            Assert.AreEqual("Intercepted-true", intercepted);
        }