code: func (s *GitScanner) ScanIndex(ref string, cb GitScannerFoundPointer) error {
  	callback, err := firstGitScannerCallback(cb, s.FoundPointer)
  	if err != nil {
  		return err
  	}
  	return scanIndex(callback, ref, s.Filter)
  }
docs: // ScanIndex scans the git index for modified LFS objects.