public void Sample_ArgumentChecking()
{
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.Sample(default(ISubscribable <int>), TimeSpan.Zero));
ReactiveAssert.Throws <ArgumentOutOfRangeException>(() => Subscribable.Sample(DummySubscribable <int> .Instance, TimeSpan.FromSeconds(-1)));
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.Sample(default(ISubscribable <int>), DummySubscribable <int> .Instance));
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.Sample(DummySubscribable <int> .Instance, default(ISubscribable <int>)));
}