/// <summary>
        /// Instantiates a new InteractionStream, feeds this InteractionStream with Skeleton- and DepthData and subscribes to the InteractionFrameReady event.
        /// </summary>
        /// <param name="kinectSensor">The Kinect sensor passed to the interaction stream instance.</param>
        /// <param name="interactionClient">The interaction client passed to the interaction stream instance.</param>
        /// <returns>An UserInfo stream that contains an action that disposes the interaction stream when the observable is disposed.</returns>
        public static IObservable <UserInfo[]> GetUserInfoObservable(this KinectSensor kinectSensor, IInteractionClient interactionClient)
        {
            if (kinectSensor == null)
            {
                throw new ArgumentNullException("kinect");
            }
            if (interactionClient == null)
            {
                throw new ArgumentNullException("interactionClient");
            }

            if (!kinectSensor.DepthStream.IsEnabled)
            {
                throw new InvalidOperationException("The depth stream is not enabled, but mandatory.");
            }
            if (!kinectSensor.SkeletonStream.IsEnabled)
            {
                throw new InvalidOperationException("The skeleton stream is not enabled, but mandatory.");
            }

            return(Observable.Create <UserInfo[]>(observer =>
            {
                var stream = new InteractionStream(kinectSensor, interactionClient);
                var obs = kinectSensor.GetAllFramesReadyObservable()
                          .SelectStreams((_, __) => Tuple.Create(_.Timestamp, __.Timestamp))
                          .Subscribe(_ =>
                {
                    stream.ProcessSkeleton(_.Item3, kinectSensor.AccelerometerGetCurrentReading(), _.Item4.Item1);
                    stream.ProcessDepth(_.Item2, _.Item4.Item2);
                });

                stream.GetInteractionFrameReadyObservable()
                .SelectUserInfo()
                .Subscribe(_ => observer.OnNext(_));

                return new Action(() =>
                {
                    obs.Dispose();
                    stream.Dispose();
                });
            }));
        }