857. The testator may, with the limitation specified in article 852, modify, restrict or extend the powers, the obligations, and the seizin of the testamentary executor, and the duration of his or her functions. He or she may constitute the testamentary executor an administrator of his property, in whole or in part, and may even give him or her the power to alienate it with or without the intervention of the heir or legatee, in the manner and for the purposes determined by himself or herself. (Amended by Act 34 of 1956)