code: func DatastoreFolderFromObject(client *govmomi.Client, obj interface{}, relative string) (*object.Folder, error) {
  	folder, err := folderFromObject(client, obj, RootPathParticleDatastore, relative)
  	if err != nil {
  		return nil, err
  	}
  
  	return validateDatastoreFolder(folder)
  }
docs: // DatastoreFolderFromObject returns an *object.Folder from a given object,
  // and relative datastore folder path. If no such folder is found, of if it is
  // not a datastore folder, an appropriate error will be returned.