code: func (n *Node) applyUpdateNode(ctx context.Context, cc raftpb.ConfChange) error {
  	newMember := &api.RaftMember{}
  	err := proto.Unmarshal(cc.Context, newMember)
  	if err != nil {
  		return err
  	}
  
  	if newMember.RaftID == n.Config.ID {
  		return nil
  	}
  	if err := n.transport.UpdatePeer(newMember.RaftID, newMember.Addr); err != nil {
  		return err
  	}
  	return n.cluster.UpdateMember(newMember.RaftID, newMember)
  }
docs: // applyUpdateNode is called when we receive a ConfChange from a member in the
  // raft cluster which update the address of an existing node.