directory/directory_transport.go
func (ref dirReference) layerPath(digest digest.Digest) string {
	// FIXME: Should we keep the digest identification?
	return filepath.Join(ref.path, digest.Hex())
}
func (ref dirReference) layerPath(digest digest.Digest) string {
	// FIXME: Should we keep the digest identification?
	return filepath.Join(ref.path, digest.Hex())
}
// layerPath returns a path for a layer tarball within a directory using our conventions.