What is the test for establishing juror misconduct?

To determine whether a party has established juror misconduct, "[t]he trial court must first 'determine whether the affidavits supporting the motion are admissible. [Citation.]' [Citation.] This, like any issue of admissibility, we review for abuse of discretion. [Citation.] [] Second, 'If the evidence is admissible, the trial court must determine whether the facts establish misconduct. [Citation.]' [Citation.] . . . [Citation.] On review from a trial court's 'determin[ation of] whether misconduct occurred, "[w]e accept the trial court's credibility determinations and findings on questions of historical fact if supported by substantial evidence. [Citations.]"' [Citations.] [] '"Lastly, assuming misconduct, the trial court must determine whether the misconduct was prejudicial."'" (Barboni v. Tuomi (2012) 210 Cal.App.4th 340, 345.) We review the issue of prejudice independently. (People v. Nesler (1997) 16 Cal.4th 561, 582-583.)