code: func (s *Scheme) AddDeepCopyFuncs(deepCopyFuncs ...interface{}) error {
  	for _, f := range deepCopyFuncs {
  		if err := s.cloner.RegisterDeepCopyFunc(f); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // AddDeepCopyFuncs adds functions to the list of deep copy functions.
  // Note that to copy sub-objects, you can use the conversion.Cloner object that
  // will be passed to your deep-copy function.