checksInstalled bool
	clock           clock.Clock
}

func (reg *healthCheckRegistry) addHealthChecks(checks ...healthz.HealthChecker) error {
	return reg.addDelayedHealthChecks(0, checks...)
}

func (reg *healthCheckRegistry) addDelayedHealthChecks(delay time.Duration, checks ...healthz.HealthChecker) error {
	if delay > 0 && reg.clock == nil {
		return fmt.Errorf("nil clock in healthCheckRegistry for %s endpoint", reg.path)
	}