code: func install(groupFactoryRegistry announced.APIGroupFactoryRegistry, registry *registered.APIRegistrationManager, scheme *runtime.Scheme) {
  	if err := announced.NewGroupMetaFactory(
  		&announced.GroupMetaFactoryArgs{
  			GroupName:                  metrics.GroupName,
  			VersionPreferenceOrder:     []string{metrics_api.SchemeGroupVersion.Version},
  			RootScopedKinds:            sets.NewString("NodeMetrics"),
  			AddInternalObjectsToScheme: metrics.AddToScheme,
  		},
  		announced.VersionToSchemeFunc{
  			metrics_api.SchemeGroupVersion.Version: metrics_api.AddToScheme,
  		},
  	).Announce(groupFactoryRegistry).RegisterAndEnable(registry, scheme); err != nil {
  		panic(err)
  	}
  }
docs: // This function is directly copied from https://github.com/kubernetes/metrics/blob/master/pkg/apis/metrics/install/install.go#L31 with only changes by replacing v1beta1 to v1alpha1.
  // This function should be deleted only after move metrics to v1beta1.
  // Install registers the API group and adds types to a scheme