code: func canBeExposed(kind schema.GroupKind) error {
  	switch kind {
  	case
  		corev1.SchemeGroupVersion.WithKind("ReplicationController").GroupKind(),
  		corev1.SchemeGroupVersion.WithKind("Service").GroupKind(),
  		corev1.SchemeGroupVersion.WithKind("Pod").GroupKind(),
  		appsv1.SchemeGroupVersion.WithKind("Deployment").GroupKind(),
  		appsv1.SchemeGroupVersion.WithKind("ReplicaSet").GroupKind(),
  		extensionsv1beta1.SchemeGroupVersion.WithKind("Deployment").GroupKind(),
  		extensionsv1beta1.SchemeGroupVersion.WithKind("ReplicaSet").GroupKind():
  		// nothing to do here
  	default:
  		return fmt.Errorf("cannot expose a %s", kind)
  	}
  	return nil
  }
docs: // Check whether the kind of resources could be exposed