public async void What_Is_The_Behavior_Of_Observable_FromEvent() { //Arrange var testTarget = new MyTest(); //testTarget.TestStarted += HandleTestStarted; //testTarget.OnTestStart(); var observableTarget = Observable.FromEventPattern(h => testTarget.TestStarted += h, h => testTarget.TestStarted -= h); IObserver <EventPattern <object> > testObserver = new TestObserver(HandleTestStarted); //observableTarget.Subscribe(testObserver); var myTask = observableTarget.Timeout(TimeSpan.FromSeconds(1)).ToTask(); await myTask; testTarget.OnTestStart(); }