code: func (az *Cloud) GetZoneByProviderID(ctx context.Context, providerID string) (cloudprovider.Zone, error) {
  	// Returns nil for unmanaged nodes because azure cloud provider couldn't fetch information for them.
  	if az.IsNodeUnmanagedByProviderID(providerID) {
  		klog.V(2).Infof("GetZoneByProviderID: omitting unmanaged node %q", providerID)
  		return cloudprovider.Zone{}, nil
  	}
  
  	nodeName, err := az.vmSet.GetNodeNameByProviderID(providerID)
  	if err != nil {
  		return cloudprovider.Zone{}, err
  	}
  
  	return az.GetZoneByNodeName(ctx, nodeName)
  }
docs: // GetZoneByProviderID implements Zones.GetZoneByProviderID
  // This is particularly useful in external cloud providers where the kubelet
  // does not initialize node data.