protected override void RealTestOutPut()
{
var tracker = new DataTracker();
var tracker1 = new DataObserver("tracker1");
var tracker2 = new DataObserver("tracker2");
tracker1.Subscribe(tracker);
tracker2.Subscribe(tracker);
tracker.Track(new DataSource()
{
a = 888
});
tracker1.UnSubscribe();
tracker.Track(new DataSource()
{
a = 233
});
tracker.Track(null);
}