code: func getISCSISessionCHAPInfo(spec *volume.Spec) (bool, error) {
  	if spec.Volume != nil && spec.Volume.ISCSI != nil {
  		return spec.Volume.ISCSI.SessionCHAPAuth, nil
  	} else if spec.PersistentVolume != nil &&
  		spec.PersistentVolume.Spec.ISCSI != nil {
  		return spec.PersistentVolume.Spec.ISCSI.SessionCHAPAuth, nil
  	}
  
  	return false, fmt.Errorf("Spec does not reference an ISCSI volume type")
  }
docs: // get iSCSI Session CHAP boolean