What is the test for instructing a jury on a defense for which the record contains substantial evidence?

A trial court must instruct on a defense "for which the record contains substantial evidence [citation]evidence sufficient for a reasonable jury to find in favor of the defendant . . . ." (People v. Salas (2006) 37 Cal.4th 967, 982.) "In determining whether the evidence is sufficient to warrant a jury instruction, the trial court does not determine the credibility of the defense evidence, but only whether 'there was evidence which, if believed by the jury, was sufficient to raise a reasonable doubt . . . .' [Citations.]" (Ibid.) Any doubt as to the sufficiency of the evidence to warrant such an instruction should be resolved in the defendant's favor. (People v. Tufunga (1999) 21 Cal.4th 935, 944.) We review de novo the trial court's refusal to give a requested instruction. (People v. Waidla (2000) 22 Cal.4th 690, 733.)