code: func (g *Cloud) GetZoneByProviderID(ctx context.Context, providerID string) (cloudprovider.Zone, error) {
  	_, zone, _, err := splitProviderID(providerID)
  	if err != nil {
  		return cloudprovider.Zone{}, err
  	}
  	region, err := GetGCERegion(zone)
  	if err != nil {
  		return cloudprovider.Zone{}, err
  	}
  	return cloudprovider.Zone{FailureDomain: zone, Region: region}, nil
  }
docs: // GetZoneByProviderID implements Zones.GetZoneByProviderID
  // This is particularly useful in external cloud providers where the kubelet
  // does not initialize node data.