In People v. Field (1995) 31 Cal.App.4th 1778, the court held that a witness in a criminal prosecution whose prior conviction had been expunged could not be impeached with the conviction. (Id. at pp. 1784-1787.) In so concluding, however, the court noted that expungement under Penal Code section 1203.4 "does not obliterate a conviction for all purposes," and that a conviction so expunged "may be considered by licensing authorities." (People v. Field, at p. 1787.)