// namespace.
func (s *SelectionPredicate) MatchesSingleNamespace() (string, bool) {
	if len(s.Continue) > 0 || s.Field == nil {
		return "", false
	}
	if namespace, ok := s.Field.RequiresExactMatch("metadata.namespace"); ok {
		return namespace, true
	}
	return "", false
}

// MatchesSingle will return (name, true) if and only if s.Field matches on the object's
// name.