  dgst, err = cc.Checksum(context.TODO(), ref, "d0/abc", true)  require.NoError(t, err)   require.Equal(t, dgstFileData0, dgst)   // symlink to the same file is followed, returns same hash  dgst, err = cc.Checksum(context.TODO(), ref, "d0/def", true)  require.NoError(t, err)   require.Equal(t, dgstFileData0, dgst)   _, err = cc.Checksum(context.TODO(), ref, "d0/