code: func (k *Kite) NewKeyRenewer(interval time.Duration) {
  	ticker := time.NewTicker(interval)
  	for range ticker.C {
  		_, err := k.GetKey()
  		if err != nil {
  			k.Log.Warning("Key renew failed: %s", err)
  		}
  	}
  }
docs: // NewKeyRenewer renews the internal key every given interval