What is the test for invoking the law of a foreign state?

"(G)enerally speaking the forum will apply its own rule of decision unless a party litigant timely invokes the law of a foreign state." (Hurtado v. Superior Court (1974) 11 Cal.3d 574, 581, 114 Cal.Rptr. 106, 110, 522 P.2d 666, 670.) Here, the question of whether defendants were authorized to operate in Arizona was never at issue in the trial court; to the contrary, the evidence showed that defendants were authorized to, and did, accept risks on behalf of Hartford for policies to be issued in Arizona. Furthermore, we note that the Arizona statutes cited by G.T.S. as controlling are, in actuality, quite similar to the California legislative scheme. (Compare Ins.Code, 1731 and 7 Ariz.Rev.Stats.Annot. (West 1975) 20-301.) As the case was tried under the assumption that California law was controlling, and since it has not been shown that pertinent Arizona law is inharmonious with the law of this state, we conclude that consideration of foreign law would be inappropriate at this stage of the proceedings.

5 The District of Columbia statute considered by the federal court read, in pertinent part, as follows: