Streams returned by flat-mappers (parallel, unordered)

[Georgiy Rakov]

Hello,

according to b85 all the flatMap-methods accept mappers returning stream 
instances (Function<T, Stream <R>>, IntFunction<IntStream>, etc.).

I wonder if spec will specify any recommendations regarding what kinds 
of streams user should or should not return from flat-mappers.
For instance:

    "If called stream is supposed to be executed in parallel then
    flat-mapper should return parallel streams or streams which could be
    converted to those by calling its parallel() method; otherwise the
    streams returned by flat-mapper will be executed sequentially."

Recommendations regarding unordered streams also seem to be interesting.

Thanks,
Georgiy.