code: func (pc *PCCloud) InstanceID(ctx context.Context, nodeName k8stypes.NodeName) (string, error) {
  	name := string(nodeName)
  	if name == pc.localK8sHostname {
  		return pc.localInstanceID, nil
  	}
  	// We assume only master need to get InstanceID of a node other than itself
  	id, err := getInstanceID(pc, name)
  	if err != nil {
  		klog.Errorf("Photon Cloud Provider: getInstanceID failed for InstanceID. Error[%v]", err)
  	}
  	return id, err
  
  }
docs: // InstanceID returns the cloud provider ID of the specified instance.