public void Any_ArgumentChecking()
{
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.Any(default(IObservable <int>)));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.Any(DummyObservable <int> .Instance, default));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.Any(default(IObservable <int>), x => true));
}