What is the legal test used to determine whether a federal court made a structural error in making a jury nullification instruction?

Having determined that the district court's jury nullification instruction did not amount to a structural error, we next proceed to the second step of our analysis, at which we must determine whether the district court's error was constitutional in nature. If an error is constitutional, the rule announced in Chapman applies and an error may only be deemed harmless if its harmlessness is clear beyond a reasonable doubt. See United States v. Perkins , 937 F.2d 1397, 1407 n.2 (9th Cir. 1991) (O'Scannlain, J., dissenting) (describing three possible levels of harmless-error scrutiny in the criminal context); United States v. ValleValdez , 554 F.2d 911, 915 (9th Cir. 1977). By contrast, "nonconstitutional errors are measured against

[880 F.3d 1035]