In People v. Toscano (2004) 124 Cal.App.4th 340, the parties explicitly included in a written agreement the defendant's entitlement to litigate both the constitutional validity of his waiver of rights in his prior conviction (e.g., People v. Sumstine (1984) 36 Cal.3d 909) and his entitlement to an exercise of the court's discretion to strike the conviction in the interests of justice ( 1385). (Toscano, supra, 124 Cal.App.4th at p. 342.) However, the sentencing judge--confronted with a substitute prosecutor who had misinterpreted the scope of the bargain and was unprepared to litigate the Sumstine challenge (based on a shorthand oral representation of the original prosecutor at the plea hearing)--found the terms ambiguous and afforded the defendant only the choice between withdrawing his plea or forfeiting his Sumstine challenge; the defendant chose the latter reluctantly. (Toscano, supra, at pp. 343-344.) Toscano did not find anything ambiguous about the plea agreement; alternatively, if there were indeed a conflict between the written agreement and the oral representation, the defendant was entitled to enforce the favorable interpretation. (Id. at pp. 344-345.)