When an accomplice is called as a witness by the prosecution, is the jury required to distrust the testimony of their accomplice's testimony?

"The law on this question is clear. When an accomplice is called as a witness by the prosecution, the court must instruct the jurors sua sponte to distrust [an accomplice's] testimony. [Citations.] When, by contrast, he is called by the defendant, the instruction should be given only at the defendant's request. [Citations.] Finally, when he is called by both parties, the instruction should be tailored to relate only to his testimony on behalf of the prosecution. [Citations.]" (People v. Williams (1988) 45 Cal.3d 1268, 1314, 248 Cal.Rptr. 834, 756 P.2d 221.)