def shift
      updated_queue = []
      found_job = nil
      @queue.each do |job|
        if found_job || job.status == Executor::STATUS_HOLDING
          updated_queue.push(job)
        elsif job.status == Executor::STATUS_NONE
          found_job = job
        end
      end
      @queue = updated_queue
      @time_start = Time.now if @time_start == nil
      return found_job
    end
def shift
      updated_queue = []
      found_job = nil
      @queue.each do |job|
        if found_job || job.status == Executor::STATUS_HOLDING
          updated_queue.push(job)
        elsif job.status == Executor::STATUS_NONE
          found_job = job
        end
      end
      @queue = updated_queue
      @time_start = Time.now if @time_start == nil
      return found_job
    end
Take something from the queue