code: func (t *osCinderCSITranslator) TranslateCSIPVToInTree(pv *v1.PersistentVolume) (*v1.PersistentVolume, error) {
  	if pv == nil || pv.Spec.CSI == nil {
  		return nil, fmt.Errorf("pv is nil or CSI source not defined on pv")
  	}
  
  	csiSource := pv.Spec.CSI
  
  	cinderSource := &v1.CinderPersistentVolumeSource{
  		VolumeID: csiSource.VolumeHandle,
  		FSType:   csiSource.FSType,
  		ReadOnly: csiSource.ReadOnly,
  	}
  
  	pv.Spec.CSI = nil
  	pv.Spec.Cinder = cinderSource
  	return pv, nil
  }
docs: // TranslateCSIPVToInTree takes a PV with CSIPersistentVolumeSource set and
  // translates the Cinder CSI source to a Cinder In-tree source.