In In re Billy M. (1983) 139 Cal. App. 3d 973, the court concluded that "Since the intent of Welfare and Institutions Code section 726 is to insure a minor is not subject to confinement for a term in excess of that to which an adult convicted of the same offense or offenses is subject, there is no need to stay concurrent terms absent a showing the length of the juvenile's term is increased by such disposition. Although unstayed and concurrent sentencing under these circumstances involves multiple punishment because the defendant is subjected to the term of both sentences even though served simultaneously , this treatment has not been shown to affect he duration of the juvenile's confinement." (In re Billy M., supra, at p. 979.)