code: func CreateJoinControlPlaneKubeConfigFiles(outDir string, cfg *kubeadmapi.InitConfiguration) error {
  	return createKubeConfigFiles(
  		outDir,
  		cfg,
  		kubeadmconstants.AdminKubeConfigFileName,
  		kubeadmconstants.ControllerManagerKubeConfigFileName,
  		kubeadmconstants.SchedulerKubeConfigFileName,
  	)
  }
docs: // CreateJoinControlPlaneKubeConfigFiles will create and write to disk the kubeconfig files required by kubeadm
  // join --control-plane workflow, plus the admin kubeconfig file used by the administrator and kubeadm itself; the
  // kubelet.conf file must not be created because it will be created and signed by the kubelet TLS bootstrap process.
  // If any kubeconfig files already exists, it used only if evaluated equal; otherwise an error is returned.