modified.Insert(k)
		}
	}
	for k, v1 := range b {
		if v2, ok := a[k]; !ok || v1 != v2 {
			modified.Insert(k)
		}
	}
	return modified
}

func isKubernetesLabel(key string) bool {
	namespace := getLabelNamespace(key)
	if namespace == "kubernetes.io" || strings.HasSuffix(namespace, ".kubernetes.io") {
		return true
	}

func ValidateKubeletFlags(f *KubeletFlags) error {
	unknownLabels := sets.NewString()
	invalidLabelErrs := make(map[string][]string)
	for k, v := range f.NodeLabels {
		if isKubernetesLabel(k) && !kubeletapis.IsKubeletLabel(k) {
			unknownLabels.Insert(k)
		}

		if errs := validation.IsQualifiedName(k); len(errs) > 0 {
			invalidLabelErrs[k] = append(invalidLabelErrs[k], errs...)
		}