code: func (s *LocalStore) SetHTTPChallengeToken(token, domain string, keyAuth []byte) error {
  	s.lock.Lock()
  	defer s.lock.Unlock()
  
  	if s.storedData.HTTPChallenges == nil {
  		s.storedData.HTTPChallenges = map[string]map[string][]byte{}
  	}
  
  	if _, ok := s.storedData.HTTPChallenges[token]; !ok {
  		s.storedData.HTTPChallenges[token] = map[string][]byte{}
  	}
  
  	s.storedData.HTTPChallenges[token][domain] = keyAuth
  	return nil
  }
docs: // SetHTTPChallengeToken Set the http challenge token in the store