Kekuatan akta jaminan fidusia dan penyelesaian eksekusi terhadap objek jaminan fidusia yang diperjualbelikan oleh debitur : studi kasus antara PT X dan Bank X di Kota Bekasi = The strength of fiduciary guarantee deed and execution completion of fiduciary guarantee objects that has been sold by debtor : case study between PT X and Bank X in Bekasi City