code: func (u *storageosUtil) DeleteVolume(d *storageosDeleter) error {
  	if err := u.NewAPI(d.apiCfg); err != nil {
  		return err
  	}
  
  	// Deletes must be forced as the StorageOS API will not normally delete
  	// volumes that it thinks are mounted.  We can't be sure the unmount was
  	// registered via the API so we trust k8s to only delete volumes it knows
  	// are unmounted.
  	opts := storageostypes.DeleteOptions{
  		Name:      d.volName,
  		Namespace: d.volNamespace,
  		Force:     true,
  	}
  	return u.api.VolumeDelete(opts)
  }
docs: // Deletes a StorageOS volume.  Assumes it has already been unmounted and detached.