// a copy of root cert from config map for verification.
	certItem0 := loadCert(rotator)

	// Change grace period percentage to 0, so that root cert is not going to expire soon.
	rotator.config.certInspector = certutil.NewCertUtil(0)
	rotator.checkAndRotateRootCert()
	// Verifies that when root cert remaining life is not in grace period time,
	// root cert is not rotated.
	certItem1 := loadCert(rotator)

	}
}

func (s *Server) RotateDNSCertForK8sCA(stop <-chan struct{},
	defaultCACertPath string,
	signerName string,
	approveCsr bool,
	requestedLifetime time.Duration,
) {
	certUtil := certutil.NewCertUtil(int(defaultCertGracePeriodRatio * 100))
	for {
		waitTime, _ := certUtil.GetWaitTime(s.istiodCertBundleWatcher.GetKeyCertBundle().CertPem, time.Now())
		if !sleep.Until(stop, waitTime) {
			return
		}

			CheckInterval:      rootCertCheckInverval,
			caCertTTL:          caCertTTL,
			retryInterval:      cmd.ReadSigningCertRetryInterval,
			retryMax:           cmd.ReadSigningCertRetryMax,
			certInspector:      certutil.NewCertUtil(rootCertGracePeriodPercentile),
			caStorageNamespace: namespace,
			dualUse:            dualUse,
			org:                org,
			rootCertFile:       rootCertFile,
			enableJitter:       enableJitter,