code: func (b *LRUCache) GetStaleNow(key string, now time.Time) (value interface{}, ok, expired bool) {
  	b.lock.Lock()
  	defer b.lock.Unlock()
  
  	e := b.table[key]
  	if e == nil {
  		return nil, false, false
  	}
  
  	b.touchEntry(e)
  	return e.value, true, e.expire.Before(now)
  }
docs: // GetStaleNow gets a key from the cache, possibly stale. Update its LRU
  // score. O(1) always.