code: func SetJoinControlPlaneDefaults(cfg *kubeadmapi.JoinControlPlane) error {
  	if cfg != nil {
  		if err := SetAPIEndpointDynamicDefaults(&cfg.LocalAPIEndpoint); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // SetJoinControlPlaneDefaults checks and sets configuration values for the JoinControlPlane object