def busy?
      busy = false
      @mutex.synchronize { busy = @thread_name_to_queue.any? { |_, q| q.busy? } }
      busy
    end
def busy?
      busy = false
      @mutex.synchronize { busy = @thread_name_to_queue.any? { |_, q| q.busy? } }
      busy
    end
Determines if queue is busy

 === Return
 active(Boolean):: true if queue is busy