# File lib/rufus/scheduler.rb, line 419
    def work_threads(query=:all)

      ts =
        threads.select { |t|
          t[:rufus_scheduler_job] || t[:rufus_scheduler_work_thread]
        }

      case query
        when :active then ts.select { |t| t[:rufus_scheduler_job] }
        when :vacant then ts.reject { |t| t[:rufus_scheduler_job] }
        else ts
      end
    end