That's some bullshit. Just take the class, see if you can get one of your non-smoking friends to give you clean piss if there's a drug test as a part of the class. But I'm surprised that you just went ahead and pissed in the cup. You should have asked for probable cause.. which... there wasn't any. You weren't high, you didn't have any weed or paraphenalia on you. That really sucks. What is this country coming to?

I have a dream that people can be judged on the content of their character, and not the content of their piss.