Kedudukan Kuitansi Kosong pada Perjanjian Utang Piutang Dilakukan Secara di Bawah Tangan yang Mengakibatkan Jual Beli Tanah (Studi Putusan Mahkamah Agung Nomor 448K/Pdt/2021) = The Legal Standing of Empty Receipts in Debt and Credit Agreements Conducted Under Hand Which Resulted in the Sale and Purchase of Land (Study of Supreme Court Decision Number 448K/Pdt/2021)