code: func UDPRemoteForwardHandler(raddr string, opts ...HandlerOption) Handler {
  	h := &udpRemoteForwardHandler{
  		raddr: raddr,
  		group: NewNodeGroup(),
  	}
  
  	for i, addr := range strings.Split(raddr, ",") {
  		if addr == "" {
  			continue
  		}
  		// We treat the remote target server as a node, so we can put them in a group,
  		// and perform the node selection for load balancing.
  		h.group.AddNode(Node{
  			ID:   i + 1,
  			Addr: addr,
  			Host: addr,
  		})
  	}
  
  	h.Init(opts...)
  
  	return h
  }
docs: // UDPRemoteForwardHandler creates a server Handler for UDP remote port forwarding server.
  // The raddr is the remote address that the server will forward to.
  // NOTE: as of 2.6, remote address can be a comma-separated address list.