}
	return meta.GetResourceVersion(), nil
}

// Patch applies only the modifications made in the PatchFunc rather than doing a full replace. Useful to avoid
// read-modify-write conflicts when there are many concurrent-writers to the same resource.
func (cl *Client) Patch(orig config.Config, patchFn config.PatchFunc) (string, error) {
	modified, patchType := patchFn(orig.DeepCopy())

		m          = make(map[string]string)
	)

	// Get all service resources from the master (via a cache),
	// and populate them into service environment variables.
	if kl.serviceLister == nil {
		// Kubelets without masters (e.g. plain GCE ContainerVM) don't set env vars.
		return m, nil
	}
	services, err := kl.serviceLister.List(labels.Everything())
	if err != nil {
		return m, fmt.Errorf("failed to list services when setting up env vars")