}
	}()
	wg.Wait()
	return s
}

func (s *fakeDNSServer) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
	s.mu.Lock()
	defer s.mu.Unlock()

	msg := (&dns.Msg{}).SetReply(r)
	if s.failure {
		msg.Rcode = dns.RcodeServerFailure
	} else {
		domain := msg.Question[0].Name
		c, ok := s.hosts[domain]
		if ok {
			s.hosts[domain]++
			switch r.Question[0].Qtype {