code: func getISCSITargetInfo(spec *volume.Spec) (string, []string, string, int32, error) {
  	if spec.Volume != nil && spec.Volume.ISCSI != nil {
  		return spec.Volume.ISCSI.TargetPortal, spec.Volume.ISCSI.Portals, spec.Volume.ISCSI.IQN, spec.Volume.ISCSI.Lun, nil
  	} else if spec.PersistentVolume != nil &&
  		spec.PersistentVolume.Spec.ISCSI != nil {
  		return spec.PersistentVolume.Spec.ISCSI.TargetPortal, spec.PersistentVolume.Spec.ISCSI.Portals, spec.PersistentVolume.Spec.ISCSI.IQN, spec.PersistentVolume.Spec.ISCSI.Lun, nil
  	}
  
  	return "", nil, "", 0, fmt.Errorf("Spec does not reference an ISCSI volume type")
  }
docs: // get iSCSI target info: target portal, portals, iqn, and lun