code: func scanLeftRightToChan(scanner *GitScanner, pointerCb GitScannerFoundPointer, refLeft, refRight string, opt *ScanRefsOptions) error {
  	return scanRefsToChan(scanner, pointerCb, []string{refLeft, refRight}, nil, opt)
  }
docs: // scanLeftRightToChan takes a ref and returns a channel of WrappedPointer objects
  // for all Git LFS pointers it finds for that ref.
  // Reports unique oids once only, not multiple times if >1 file uses the same content