'Run *nprocs* processes extracting randomness
without explicit seeding.'

def extract_in_processes(self, nprocs, extract_randomness):

    q = multiprocessing.Queue()
    results = []
    def target_inner():
        out = self._get_output(self._extract_iterations)
        extract_randomness(seed=0, out=out)
        return out
    def target():
        try:
            out = target_inner()
            q.put(out)
        except Exception as e:
            q.put(e)
            raise
    procs = [multiprocessing.Process(target=target) for i in range(nprocs)]
    for p in procs:
        p.start()
    for i in range(nprocs):
        results.append(q.get(timeout=5))
    for p in procs:
        p.join()
    results.append(target_inner())
    for res in results:
        if isinstance(res, Exception):
            self.fail(('Exception    in    child:    %s' % (res,)))
    return results
