What is the test for credibility of a witness in a sexual assault case?

credible, and of solid value, nonetheless it is the exclusive province of the trial judge or jury to determine the credibility of a witness and the truth or falsity of the facts on which that determination depends. [Citation.] Thus, if the verdict is supported by substantial evidence, we must accord due deference to the trier of fact and not substitute our evaluation of a witness's credibility for that of the fact finder. [Citations.]" ' " (People v. Smith (2005) 37 Cal.4th 733, 738-739.)

" 'Conflicts and even testimony which is subject to justifiable suspicion do not justify the reversal of a judgment, for it is the exclusive province of the trial judge or jury to determine the credibility of a witness and the truth or falsity of the facts upon which a determination depends.' [Citation.] Unless it describes facts or events that are physically impossible or inherently improbable, the testimony of a single witness is sufficient to support a conviction. [Citation.]" (People v. Elliott (2012) 53 Cal.4th 535, 585.)