code: func checkGeoKey() error {
  	if _, err := geocode.GetAPIKey(); err == nil {
  		return nil
  	}
  	keyPath, err := geocode.GetAPIKeyPath()
  	if err != nil {
  		return fmt.Errorf("error getting Geocoding API key path: %v", err)
  	}
  	if env.OnGCE() {
  		keyPath = strings.TrimPrefix(keyPath, "/gcs/")
  		return fmt.Errorf("for location related requests to properly work, you need to create a Google Geocoding API Key (see https://developers.google.com/maps/documentation/geocoding/get-api-key ), and save it in your VM's configuration bucket as: %v", keyPath)
  	}
  	return fmt.Errorf("for location related requests to properly work, you need to create a Google Geocoding API Key (see https://developers.google.com/maps/documentation/geocoding/get-api-key ), and save it in Perkeep's configuration directory as: %v", keyPath)
  }
docs: // checkGeoKey returns nil if we have a Google Geocoding API key file stored
  // in the config dir. Otherwise it returns instruction about it as the error.