code: func (c *cache) SaveFile(fname string) error {
  	fp, err := os.Create(fname)
  	if err != nil {
  		return err
  	}
  	err = c.Save(fp)
  	if err != nil {
  		fp.Close()
  		return err
  	}
  	return fp.Close()
  }
docs: // Save the cache's items to the given filename, creating the file if it
  // doesn't exist, and overwriting it if it does.
  //
  // NOTE: This method is deprecated in favor of c.Items() and NewFrom() (see the
  // documentation for NewFrom().)