code: func (plugin *cinderPlugin) NewBlockVolumeMapper(spec *volume.Spec, pod *v1.Pod, _ volume.VolumeOptions) (volume.BlockVolumeMapper, error) {
  	// If this is called via GenerateUnmapDeviceFunc(), pod is nil.
  	// Pass empty string as dummy uid since uid isn't used in the case.
  	var uid types.UID
  	if pod != nil {
  		uid = pod.UID
  	}
  
  	return plugin.newBlockVolumeMapperInternal(spec, uid, &DiskUtil{}, plugin.host.GetMounter(plugin.GetPluginName()))
  }
docs: // NewBlockVolumeMapper creates a new volume.BlockVolumeMapper from an API specification.