code: func (s *storage) RemoveBlobs(ctx context.Context, blobs []blob.Ref) error {
  	batch := s.index.BeginBatch()
  	var wg syncutil.Group
  	for _, br := range blobs {
  		br := br
  		removeGate.Start()
  		batch.Delete(br.String())
  		wg.Go(func() error {
  			defer removeGate.Done()
  			if err := s.delete(br); err != nil && err != os.ErrNotExist {
  				return err
  			}
  			return nil
  		})
  	}
  	err1 := wg.Err()
  	err2 := s.index.CommitBatch(batch)
  	if err1 != nil {
  		return err1
  	}
  	return err2
  }
docs: // RemoveBlobs removes the blobs from index and pads data with zero bytes