code: func (az *Cloud) GetIPForMachineWithRetry(name types.NodeName) (string, string, error) {
  	var ip, publicIP string
  	err := wait.ExponentialBackoff(az.requestBackoff(), func() (bool, error) {
  		var retryErr error
  		ip, publicIP, retryErr = az.vmSet.GetIPByNodeName(string(name))
  		if retryErr != nil {
  			klog.Errorf("GetIPForMachineWithRetry(%s): backoff failure, will retry,err=%v", name, retryErr)
  			return false, nil
  		}
  		klog.V(2).Infof("GetIPForMachineWithRetry(%s): backoff success", name)
  		return true, nil
  	})
  	return ip, publicIP, err
  }
docs: // GetIPForMachineWithRetry invokes az.getIPForMachine with exponential backoff retry