// FieldsSelectorParam adds the given selector as a query parameter with the name paramName.
func (r *Request) FieldsSelectorParam(s fields.Selector) *Request {
	if r.err != nil {
		return r
	}
	if s.Empty() {
		return r
	}
	s2, err := s.Transform(func(field, value string) (newField, newValue string, err error) {
		return fieldMappings.filterField(r.apiVersion, r.resource, field, value)
	})
	if err != nil {
		r.err = err
		return r
	}
	return r.setParam(api.FieldSelectorQueryParam(r.apiVersion), s2.String())
}