Kedudukan hukum surat hibah dibawah tangan yang dibatalkan dengan berlakunya akta hibah wasiat (studi kasus putusan pengadilan tinggi nomor 371/PDT/2017/PT.DKI) = Legal standing of privately made letter of grant that is canceled with the enactment of the testamentary grant case study of high court verdict number 371/PDT.2017/PT.DKI