code: func (bl *blackList) insert(ip string, port int) {
  	if bl.list.Len() >= bl.maxSize {
  		return
  	}
  
  	bl.list.Set(bl.genKey(ip, port), &blockedItem{
  		ip:         ip,
  		port:       port,
  		createTime: time.Now(),
  	})
  }
docs: // insert adds a blocked item to the blacklist.