def maintain_worker_count
      all_known_queues.each do |queues|
        delta = worker_delta_for(queues)
        spawn_missing_workers_for(queues) if delta > 0
        quit_excess_workers_for(queues)   if delta < 0
      end
    end
def maintain_worker_count
      all_known_queues.each do |queues|
        delta = worker_delta_for(queues)
        spawn_missing_workers_for(queues) if delta > 0
        quit_excess_workers_for(queues)   if delta < 0
      end
    end
}}}
 ???: maintain_worker_count, all_known_queues {{{