nestmates spec open issues

[John Rose]

On Oct 25, 2017, at 3:33 PM, Remi Forax <forax at univ-mlv.fr> wrote:
> 
> getClasses() throws an exception but getAnnotations() skips unavailable annotations.
> 
> that said, i'm not against throwing in this case.

I'm not against throwing either, but I think scrubbing (like annotations)
is a little better, because it is more robust about retaining partial results.
Partial results are important if you are just asking about one or two
classes and don't care about their other nestmates.