code: func (c *Cluster) AddMember(member *Member) error {
  	c.mu.Lock()
  	defer c.mu.Unlock()
  
  	if c.removed[member.RaftID] {
  		return ErrIDRemoved
  	}
  
  	c.members[member.RaftID] = member
  
  	c.broadcastUpdate()
  	return nil
  }
docs: // AddMember adds a node to the Cluster Memberlist.