code: func (q *queue) ExpireHeaders(timeout time.Duration) map[string]int {
  	q.lock.Lock()
  	defer q.lock.Unlock()
  
  	return q.expire(timeout, q.headerPendPool, q.headerTaskQueue, headerTimeoutMeter)
  }
docs: // ExpireHeaders checks for in flight requests that exceeded a timeout allowance,
  // canceling them and returning the responsible peers for penalisation.