static void Main(string[] args)
{
var observable = new MyRangeObservable(5, 8);
var subscription = observable.Subscribe();
Console.WriteLine("Press any key to exit the program...");
Console.ReadKey();
}
static void Demo()
{
var observable = new MyRangeObservable(5, 8);
var observer = new MyObserver <int>();
var subscription = observable.Subscribe(observer);
Console.WriteLine("Press any key to dispose the subscription");
Console.ReadKey();
subscription.Dispose();
}