public void I_should_be_able_to_retrieve_a_single_message_by_position()
        {
            PingMessage ping = new PingMessage();
            PongMessage pong = new PongMessage();

            MessageGroup group = MessageGroup.Build <MessageGroup>()
                                 .Add(ping)
                                 .Add(pong);

            PingMessage thePing = group.Get <PingMessage>(0);
        }
        public void I_should_get_an_exception_when_I_try_to_get_an_unmatched_type()
        {
            PingMessage ping = new PingMessage();
            PongMessage pong = new PongMessage();

            MessageGroup group = MessageGroup.Build <MessageGroup>()
                                 .Add(ping)
                                 .Add(pong);

            Assert.Throws <ArgumentException>(() =>
            {
                PingMessage thePing = group.Get <PingMessage>(1);
            });
        }