Cottle v. Superior Court (1992) 3 Cal. App. 4th 1367 [5 Cal. Rptr. 2d 882] involved complex litigation in which the trial court, on its own motion, issued a final order excluding evidence by the plaintiffs. In upholding this order, the court stated: "Furthermore, courts have inherent equity, supervisory and administrative powers as well as inherent power to control litigation before them. Inherent powers of the court are derived from the state Constitution and are not confined by or dependent on statute." (Id. at p. 1377, italics added.)