code: func (s *Scheme) AddFieldLabelConversionFunc(version, kind string, conversionFunc FieldLabelConversionFunc) error {
  	if s.fieldLabelConversionFuncs[version] == nil {
  		s.fieldLabelConversionFuncs[version] = map[string]FieldLabelConversionFunc{}
  	}
  
  	s.fieldLabelConversionFuncs[version][kind] = conversionFunc
  	return nil
  }
docs: // AddFieldLabelConversionFunc adds a conversion function to convert field selectors
  // of the given kind from the given version to internal version representation.