RFR [14] 8225583: Examine the HttpResponse.BodySubscribers for null handling

[Pavel Rappo]

> On 13 Jun 2019, at 17:57, Daniel Fuchs <daniel.fuchs at oracle.com> wrote:
> 
> I'd prefer to remove:
> 958             Objects.requireNonNull(throwable);

But it seems to be the crux of that change. The tests accompanying this change
verifies that behavior.