Perlindungan Hukum Terhadap Para Pihak Atas Pembatalan Perjanjian Pengikatan Jual Beli Secara Sepihak (Studi Kasus Dalam Putusan Nomor: 7/Pdt.G/2020//Pn Jkt.Ut) = LEGAL PROTECTION FOR BOTH PARTIES PUBLIC FOR CANCELLATION OF SALE AND PURCHASE AGREEMENT BY ONE OF THE PARTIES (STUDY CASE:PUTUSAN:7/PDT/G/2020/PN/JKT.UT)