Kuasa menjual yang mengabaikan pasal 1813 Kitab Undang-Undang Hukum Perdata sebagai dasar pemindahan hak atas tanah: studi putusan Mahkamah Agung nomor: 549 PK/PDT/2016 = Sale power of attorney which waived article 1813 of Indonesian Civil Code as the based on transfer on land right: case study of Supreme Court decision number: 549 PK/PDT/2016