code: func setOriginalConfiguration(obj runtime.Object, original []byte) error {
  	if len(original) < 1 {
  		return nil
  	}
  
  	annots, err := metadataAccessor.Annotations(obj)
  	if err != nil {
  		return err
  	}
  
  	if annots == nil {
  		annots = map[string]string{}
  	}
  
  	annots[v1.LastAppliedConfigAnnotation] = string(original)
  	return metadataAccessor.SetAnnotations(obj, annots)
  }
docs: // SetOriginalConfiguration sets the original configuration of the object
  // as the annotation on the object for later use in computing a three way patch.