Perlindungan hukum terhadap pembeli lelang eksekusi PUPN dalam hal objek lelang fiktif: studi kasus Putusan Mahkamah RI Nomor 1159 K/Pdt.06/2011 = Legal protection upon the buyer of PUPN auction execution in case of fictitious auction object: a case study of the decision of the Supreme Court of the Republic of Indonesia Number 1159 K/Pdt/2011 / Dressy Copperiana - Dressy Copperiana, author (2013)