code: func OpenOrCreateDataDirectory(path string) (*DataDirectory, error) {
  	exists, err := exists(path)
  	if err != nil {
  		return nil, err
  	}
  	if !exists {
  		klog.Infof("data directory '%s' does not exist, creating it", path)
  		err := os.MkdirAll(path, 0777)
  		if err != nil {
  			return nil, fmt.Errorf("failed to create data directory %s: %v", path, err)
  		}
  	}
  	versionFile := &VersionFile{
  		path: filepath.Join(path, versionFilename),
  	}
  	return &DataDirectory{path, versionFile}, nil
  }
docs: // OpenOrCreateDataDirectory opens a data directory, creating the directory
  // if it doesn't not already exist.