What is the test for determining whether a defendant acted in self-defense against an assault victim who had been threatened or assaulted prior to the assault?

In some circumstances, prior threats or assaults may be relevant in determining whether a defendant acted in self-defense. Antecedent threats or assaults may "illuminate and reflect on the reasonableness of defendant's perception of both the imminence of danger and the need to resist with the degree of force applied. [Citation.] They may also justify the defendant 'in acting more quickly and taking harsher measures for her own protection . . . .'" (People v. Humphrey (1996) 13 Cal.4th 1073, 1094.)