What is the test for a jury to convict a defendant of drug dealing?

Appellant also relies on the decision in United States v. Gaskins (9th Cir.1988) 849 F.2d 454, a case more analogous to the case at bar. In Gaskins the defendant was charged with possession of methamphetamine and with manufacturing methamphetamine. During discussions on instructions the prosecutor requested an instruction on aiding and abetting. In response, defense counsel requested a special instruction on unanimity to inform the jurors their verdict had to be unanimous on the theory of the defendant's guilt--as a principal or as an aider and abettor. Ultimately counsel agreed with the trial court's decision not to give either instruction. (849 F.2d at p. 456.)