In reviewing jury instructions, what is the test for determining whether the jury instructions as a whole are misleading or inadequate to guide deliberations?

In reviewing jury instructions, "[o]ur inquiry is whether the jury instructions as a whole are misleading or inadequate to guide the jury's deliberations." United States v. Joetzki, 952 F.2d 1090, 1095 (9th Cir.1991). The trial judge has substantial latitude in formulating jury instructions so long as the instructions fairly and adequately cover the issues presented. United States v. Powell, 955 F.2d 1206, 1210 (9th Cir.1992). Jury instructions, even if imperfect, are not a basis for overturning a conviction absent a showing that they constitute an abuse of the trial court's discretion. Joetzki, 952 F.2d at 1095.