public override Task <Terminator <TReduction> > InvokeAsync(TReduction reduction, T value) =>
Container.Push(value) ? Next.InvokeAsync(reduction, Container.Window)
: Task.FromResult(Reduction(reduction));
public override Terminator <TReduction> Invoke(TReduction reduction, T value) => Container.Push(value) ? Next.Invoke(reduction, Container.Window) : Reduction(reduction);
