public void DelaySubscription_ArgumentChecking()
{
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(default(IObservable <int>), DateTimeOffset.Now));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(default(IObservable <int>), DateTimeOffset.Now, Scheduler.Immediate));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(DummyObservable <int> .Instance, DateTimeOffset.Now, default));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(default(IObservable <int>), TimeSpan.Zero));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(default(IObservable <int>), TimeSpan.Zero, Scheduler.Immediate));
ReactiveAssert.Throws <ArgumentNullException>(() => Observable.DelaySubscription(DummyObservable <int> .Instance, TimeSpan.Zero, default));
ReactiveAssert.Throws <ArgumentOutOfRangeException>(() => Observable.DelaySubscription(DummyObservable <int> .Instance, TimeSpan.FromSeconds(-1)));
ReactiveAssert.Throws <ArgumentOutOfRangeException>(() => Observable.DelaySubscription(DummyObservable <int> .Instance, TimeSpan.FromSeconds(-1), Scheduler.Immediate));
}
