You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: nameserver.go
    path of file: ./repos/netbird/dns
    
    the code of the file until where you have to start completion: package dns

import (
	"fmt"
	"net/netip"
	"net/url"
	"strconv"
	"strings"
)

const (
	// InvalidNameServerType invalid nameserver type
	InvalidNameServerType NameServerType = iota
	// UDPNameServerType udp nameserver type
	UDPNameServerType
)

const (
	// MaxGroupNameChar maximum group name size
	MaxGroupNameChar = 40
	// InvalidNameServerTypeString invalid nameserver type as string
	InvalidNameServerTypeString = "invalid"
	// UDPNameServerTypeString udp nameserver type as string
	UDPNameServerTypeString = "udp"
)


    
func (g *NameServerGroup) Copy() *NameServerGroup {
	nsGroup := &NameServerGroup{
		ID:                   g.ID,
		Name:                 g.Name,
		Description:          g.Description,
		NameServers:          make([]NameServer, len(g.NameServers)),
		Groups:               make([]string, len(g.Groups)),
		Enabled:              g.Enabled,
		Primary:              g.Primary,
		Domains:              make([]string, len(g.Domains)),
		SearchDomainsEnabled: g.SearchDomainsEnabled,
	}

	copy(nsGroup.NameServers, g.NameServers)
	copy(nsGroup.Groups, g.Groups)
	copy(nsGroup.Domains, g.Domains)

	return nsGroup
}