California courts have followed the general rule that when a federal claim is brought in state court the law of the state controls on matters of practice and procedure but federal law controls on matters of substance. (Williams v. Horvath, supra, 16 Cal. 3d 834, 841; Chavez v. Keat (1995) 34 Cal. App. 4th 1406, 1416 [41 Cal. Rptr. 2d 72].) In Williams, the court determined the Government Code's claims filing requirement was a substantive limitation on a cause of action under section 1983, not a mere procedural rule, and therefore "is inoperative in an action brought under section 1983." (Williams at p. 842.) In Chavez, the court held the California rule which requires a plaintiff seeking punitive damages initially to offer proof of the defendant's financial status is a rule of substantive law and, thus, inapplicable to an action brought under section 1983. (Chavez at p. 1416.) Rules defining the measure of damages in a tort action are clearly substantive not procedural and therefore any conflict between federal and state law must be resolved in favor of the federal law.