public void Unsubscribe()
        {
            var server = new ParameterServer(new Uri("http://localhost"));

            var slave = new SlaveServer("test", 0, new TopicContainer());
            var observer = new ReplaySubject<KeyValuePair<string, object>>();

            slave.ParameterUpdated += (key, value) => observer.OnNext(new KeyValuePair<string, object>(key, value));

            server.SetParam("test", "test_param", 1234);

            server.SubscribeParam("test", slave.SlaveUri.ToString(), "test_param");

            server.SetParam("test", "test_param", 5678);

            server.UnsubscribeParam("test", slave.SlaveUri.ToString(), "test_param");

            server.SetParam("test", "test_param", 9999);
        }