What is the test for determining credibility of a witness who has a developmental disability?

informed the jury in regard to judging the credibility of witnesses. CALCRIM No. 331 informed the jury that it should not simply reject a witness's testimony because the witness has a developmental disability. It does not, however, purport to imbue the testimony of a developmentally disabled witness with any more credibility than any other witness. It merely informs the jury that it should not disregard the testimony of a developmentally disabled witness based solely upon the witness having a disability, just as a jury should not disregard the testimony of a child based solely on the fact that the witness is a child. (People v. McCoy (2005) 133 Cal.App.4th 974, 978-980 [rejecting the same constitutional challenges addressed to jury instruction on evaluating a young child's testimony].) The instruction did not require any particular inference from the testimony of any witness found to be developmentally disabled. (Cf. People v. Harlan (1990) 222 Cal.App.3d 439, 456 [holding CALJIC 2.20.1 did not violate right of confrontation].) Moreover, the district attorney's argument could not have led the jury to a contrary conclusion. His sole comment on this issue was: "Just because a witness comes in with a disability, they shouldn't be discounted or distrusted just because of that."