In Roybal v. University Ford (1989) 207 Cal. App. 3d 1080, the plaintiffs filed an action against the defendant in municipal court. They then filed an action in superior court, based on the same transaction, and dismissed the municipal court action with prejudice. The defendant obtained a summary judgment in the superior court action on the ground that it was barred by res judicata. (At pp. 1083-1084.) The court reviewed the common law doctrine of retraxit and the statutory provisions for voluntary dismissal of an action. ( Roybal v. University Ford, supra, 207 Cal. App. 3d at p. 1086.) It noted that "[a]lthough the statutory method of voluntary dismissal provided in [Code of Civil Procedure] section 581 . . . dispenses with the common law requirement of renunciation in open court, a dismissal with prejudice under such section has the same effect as a common law retraxit and bars any future action on the same subject matter." ( Id. at p. 1087, italics added.) It "constitute[s] a final judgment invoking the bar of res judicata." (Ibid., italics added.) Thus, summary judgment was proper. ( Id. at p. 1089.)