What is the test for possession for the purpose of trafficking?

130 In order to convict either of the appellants of possession for the purpose of trafficking, by application of the definition of possession found in s. 4(3), the jury would have to have been satisfied beyond a reasonable doubt, inter alia, that each exercised some measure of control over the marijuana in question; Regina v. Terrence, 1983 CanLII 51 (SCC), [1983] 1 S.C.R. 357. If the route to conviction was through s. 21(2), however, the jury would have been entitled to convict each of the appellants, even though they could not be shown to have exercised any control over the marijuana, so long as the jury was satisfied beyond a reasonable doubt that each had formed an intention in common to traffic in marijuana, with another accused against whom the requisite elements of possession could be proved, and that they knew or ought to have known that the offence of possession for the purpose of trafficking would be the probable consequence of that common purpose.