code: func (l *HealthzAdaptor) Check(req *http.Request) error {
  	l.pointerLock.Lock()
  	defer l.pointerLock.Unlock()
  	if l.le == nil {
  		return nil
  	}
  	return l.le.Check(l.timeout)
  }
docs: // Check is called by the healthz endpoint handler.
  // It fails (returns an error) if we own the lease but had not been able to renew it.