code: func FromUnversionedClient(c *unversioned.Client) *Clientset {
  	var clientset Clientset
  	if c != nil {
  		clientset.CoreClient = unversionedcore.New(c.RESTClient)
  	} else {
  		clientset.CoreClient = unversionedcore.New(nil)
  	}
  	if c != nil && c.ExtensionsClient != nil {
  		clientset.ExtensionsClient = unversionedextensions.New(c.ExtensionsClient.RESTClient)
  	} else {
  		clientset.ExtensionsClient = unversionedextensions.New(nil)
  	}
  
  	if c != nil && c.DiscoveryClient != nil {
  		clientset.DiscoveryClient = unversioned.NewDiscoveryClient(c.DiscoveryClient.RESTClient)
  	} else {
  		clientset.DiscoveryClient = unversioned.NewDiscoveryClient(nil)
  	}
  
  	return &clientset
  }
docs: // FromUnversionedClient adapts a pkg/client/unversioned#Client to a Clientset.
  // This function is temporary. We will remove it when everyone has moved to using
  // Clientset. New code should NOT use this function.