code: func (az *Cloud) listLBWithRetry(service *v1.Service) ([]network.LoadBalancer, error) {
  	var allLBs []network.LoadBalancer
  
  	err := wait.ExponentialBackoff(az.requestBackoff(), func() (bool, error) {
  		var retryErr error
  		ctx, cancel := getContextWithCancel()
  		defer cancel()
  
  		allLBs, retryErr = az.LoadBalancerClient.List(ctx, az.ResourceGroup)
  		if retryErr != nil {
  			az.Event(service, v1.EventTypeWarning, "ListLoadBalancers", retryErr.Error())
  			klog.Errorf("LoadBalancerClient.List(%v) - backoff: failure, will retry,err=%v",
  				az.ResourceGroup,
  				retryErr)
  			return false, retryErr
  		}
  		klog.V(2).Infof("LoadBalancerClient.List(%v) - backoff: success", az.ResourceGroup)
  		return true, nil
  	})
  	if err != nil {
  		return nil, err
  	}
  
  	return allLBs, nil
  }
docs: // listLBWithRetry invokes az.LoadBalancerClient.List with exponential backoff retry