code: func copySubElementPatchStrategy(field string, from, to map[string]interface{}) error {
  	// Check if the parent has a patch strategy extension
  	if ext, found := from["x-kubernetes-patch-strategy"]; found {
  		strategy, ok := ext.(string)
  		if !ok {
  			return fmt.Errorf("Expected string value for x-kubernetes-patch-strategy on %s, was %T",
  				field, ext)
  		}
  		// Check of the parent patch strategy has a sub patch strategy, and if so copy to the sub type
  		if strings.Contains(strategy, ",") {
  			strategies := strings.Split(strategy, ",")
  			if len(strategies) != 2 {
  				// Only 1 sub strategy is supported
  				return fmt.Errorf(
  					"Expected between 0 and 2 elements for x-kubernetes-patch-merge-strategy by got %v",
  					strategies)
  			}
  			to["x-kubernetes-patch-strategy"] = strategies[1]
  		}
  	}
  	return nil
  }
docs: // copyPatchStrategy copies the strategies to subelements to the subtype
  // e.g. PodTemplate.Volumes is a []Volume with "x-kubernetes-patch-strategy": "merge,retainKeys"
  // the "retainKeys" strategy applies to merging Volumes, and must be copied to the sub element