code: func ReplicaSetToSelectableFields(rs *apps.ReplicaSet) fields.Set {
  	objectMetaFieldsSet := generic.ObjectMetaFieldsSet(&rs.ObjectMeta, true)
  	rsSpecificFieldsSet := fields.Set{
  		"status.replicas": strconv.Itoa(int(rs.Status.Replicas)),
  	}
  	return generic.MergeFieldsSets(objectMetaFieldsSet, rsSpecificFieldsSet)
  }
docs: // ReplicaSetToSelectableFields returns a field set that represents the object.