code: func (f *sharedInformerFactory) ForResource(resource schema.GroupVersionResource) (GenericInformer, error) {
  	switch resource {
  	// Group=samplecontroller.k8s.io, Version=v1alpha1
  	case v1alpha1.SchemeGroupVersion.WithResource("foos"):
  		return &genericInformer{resource: resource.GroupResource(), informer: f.Samplecontroller().V1alpha1().Foos().Informer()}, nil
  
  	}
  
  	return nil, fmt.Errorf("no informer found for %v", resource)
  }
docs: // ForResource gives generic access to a shared informer of the matching type
  // TODO extend this to unknown resources with a client pool