California Uniform Commercial Code section 2725 provides in relevant part: "(1) An action for breach of any contract for sale must be commenced within four years after the cause of action has accrued. ... (2) A cause of action accrues when the breach occurs, regardless of the aggrieved party's lack of knowledge of the breach. A breach of warranty occurs when tender of delivery is made, except that where a warranty explicitly extends to future performance of the goods and discovery of the breach must await the time of such performance the cause of action accrues when the breach is or should have been discovered." In Kaiser Cement & Gypsum Corp. v. Allis-Chalmers Mfg. Co. (1973) 35 Cal.App.3d 948, the parties entered into their contract in 1962, and the plaintiff did not discover the breach of implied warranty until 1966 or 1967. (Kaiser, supra, 35 Cal.App.3d at pp. 952, 961-962.) Section 2725 specifically provides that the section "does not apply to causes of action which have accrued before this code becomes effective on January 1, 1968." ( 2725, subd. (4).) Thus, by its terms, section 2725's accrual-upon-tender rule was inapplicable in Kaiser. The Kaiser court relied solely on the pre-section-2725 decisions to conclude the statute of limitations did not begin to run until the breach could be reasonably discoverable by the purchaser. (Kaiser, supra, 35 Cal.App.3d at p. 960.) (3) The Jensen court likewise did not consider the issue whether the warranty was one that "explicitly extends to future performance." (Jensen, supra, 35 Cal.App.4th at pp. 132-134.) The action was filed within four years of the product delivery (id. at pp. 119-120), and therefore there was no need for the court to decide if the "future performance" exception applied (id. at pp. 132-134). Cases are not authority for propositions not considered therein. (In re Marriage of Cornejo (1996) 13 Cal.4th 381, 388 53 Cal. Rptr. 2d 81, 916 P.2d 476.) Krieger is also inapposite in that it provides an example of a warranty that explicitly extends to future performance because it contains an express time limit. The automobile warranty stated the defendant would repair defects for 36 months or the first 36,000 miles, whichever occurs first--thus creating a defined three-year outer limit for the warranty period. (Krieger, supra, 234 Cal.App.3d at p. 216.) Moreover, the Krieger court focused on the promise to repair the vehicle during the warranty period. The court stated: "A promise to repair defects that occur during a future period is the very definition of express warranty of future performance ... ." (Id. at p. 217.)