I don't understand how this is hard to understand in 2015. I guess nobody has used a coin's testnet. It's simply "fake" coins to play with for testing purposes. If you just want to play around with UNO but not spare your real coins, then you can test mine the testnet, send coins for testing without worry of losing your Unobtanium. If you don't want to play with test coins from the testnet blockchain, then do nothing with it.