Keabsahan Kepemilikan Bidang Tanah Yang Perbuatan Hukumnya Dibatalkan Oleh Pengadilan Tata Usaha Negara (Studi Kasus Putusan PTTUN Makassar No. 27/Bdg.TUN/1998/PT.THN.UPG Juncto Putusan Mahkamah Agung No. 766 PK/PDT/2012) = Validity of Land Ownership of Which Legal Act Is Nullified by State Administrative Court (Case Study of Makassar State Administrative Court [PTTUN] Decision No. 27/Bdg.TUN/1998/PT.THN.UPG in Conjunction with Supreme Court Decision No. 766 PK/PDT/2012)