public DeviceService(IConnectableObservable <IDeviceView> source)
{
_disposable.Add(source
.GroupBy(x => x.DeviceId)
.Subscribe(deviceStream => {
_disposable.Add(deviceStream
.Scan(DeviceUpdateEvent.GetInitialView(deviceStream.Key), DeviceUtils.Update)
.Subscribe(GetCreateSubject(deviceStream.Key)));
}));
_disposable.Add(source.Connect());
}