directory/directory_src.go
func (s *dirImageSource) LayerInfosForCopy(ctx context.Context) ([]types.BlobInfo, error) {
	return nil, nil
}
func (s *dirImageSource) LayerInfosForCopy(ctx context.Context) ([]types.BlobInfo, error) {
	return nil, nil
}
// LayerInfosForCopy() returns updated layer info that should be used when copying, in preference to values in the manifest, if specified.