code: func NewDNSServer(domain string) *DNSServer {
  	return &DNSServer{
  		Domain:     domain + ".",
  		aRecords:   map[string]net.IP{},
  		srvRecords: map[string][]SRVRecord{},
  		aMutex:     sync.RWMutex{},
  		srvMutex:   sync.RWMutex{},
  	}
  }
docs: // Create a new DNS server. Domain is an unqualified domain that will be used
  // as the TLD.