public void LastOrDefaultAsync_ArgumentChecking()
{
#pragma warning disable IDE0034 // Simplify 'default' expression (illustrative of method signature)
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.LastOrDefaultAsync(default(ISubscribable <int>)));
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.LastOrDefaultAsync(default(ISubscribable <int>), _ => true));
ReactiveAssert.Throws <ArgumentNullException>(() => Subscribable.LastOrDefaultAsync(DummySubscribable <int> .Instance, default(Func <int, bool>)));
#pragma warning restore IDE0034 // Simplify 'default' expression
}