func NewDeadlineWorker(timeout time.Duration) *DeadlineWorker {
	dw := &DeadlineWorker{
		timeout: timeout,
	}
	return dw
}

// Run runs the given function, passing it a stopper channel. If the deadline passes before
// the function finishes executing, Run returns context.DeadlineExceeded to the caller.
// channel so that the work function can attempt to exit gracefully.