code: func NewTarExporter(is image.Store, lss map[string]layer.Store, rs refstore.Store, loggerImgEvent LogImageEvent) image.Exporter {
  	return &tarexporter{
  		is:             is,
  		lss:            lss,
  		rs:             rs,
  		loggerImgEvent: loggerImgEvent,
  	}
  }
docs: // NewTarExporter returns new Exporter for tar packages