code: func (ih *ImageHandler) cacheScaled(ctx context.Context, thumbBytes []byte, name string) error {
  	br, err := writeToCache(ctx, ih.Cache, thumbBytes, name)
  	if err != nil {
  		return err
  	}
  	ih.ThumbMeta.Put(name, br)
  	return nil
  }
docs: // cacheScaled saves in the image handler's cache the scaled image bytes
  // in thumbBytes, and puts its blobref in the scaledImage under the key name.