code: func (s *secrets) Get(secretID string) (*api.Secret, error) {
  	s.mu.RLock()
  	defer s.mu.RUnlock()
  	if s, ok := s.m[secretID]; ok {
  		return s, nil
  	}
  	return nil, fmt.Errorf("secret %s not found", secretID)
  }
docs: // Get returns a secret by ID.  If the secret doesn't exist, returns nil.