code: func (kl *Kubelet) updateDefaultLabels(initialNode, existingNode *v1.Node) bool {
  	defaultLabels := []string{
  		v1.LabelHostname,
  		v1.LabelZoneFailureDomain,
  		v1.LabelZoneRegion,
  		v1.LabelInstanceType,
  		v1.LabelOSStable,
  		v1.LabelArchStable,
  		kubeletapis.LabelOS,
  		kubeletapis.LabelArch,
  	}
  
  	needsUpdate := false
  	if existingNode.Labels == nil {
  		existingNode.Labels = make(map[string]string)
  	}
  	//Set default labels but make sure to not set labels with empty values
  	for _, label := range defaultLabels {
  		if _, hasInitialValue := initialNode.Labels[label]; !hasInitialValue {
  			continue
  		}
  
  		if existingNode.Labels[label] != initialNode.Labels[label] {
  			existingNode.Labels[label] = initialNode.Labels[label]
  			needsUpdate = true
  		}
  
  		if existingNode.Labels[label] == "" {
  			delete(existingNode.Labels, label)
  		}
  	}
  
  	return needsUpdate
  }
docs: // updateDefaultLabels will set the default labels on the node