code: func (bl *blackList) in(ip string, port int) bool {
  	if _, ok := bl.list.Get(ip); ok {
  		return true
  	}
  
  	key := bl.genKey(ip, port)
  
  	v, ok := bl.list.Get(key)
  	if ok {
  		if time.Now().Sub(v.(*blockedItem).createTime) < bl.expiredAfter {
  			return true
  		}
  		bl.list.Delete(key)
  	}
  	return false
  }
docs: // validate checks whether ip-port pair is in the block nodes list.