Every champion enabled as a bot in a custom game.

I myself like to get in touch with a new champion that I just bought through a custom game against bots. Usually I like to get some counters in to the opposing team (Riven v Poppy etc.) but there usually comes problems with some champions because the custom game mode doesn't provide you with all the possible champions. I just think it would be a cool feature in to the game, nothing major but a small and (I'm assuming) not that hard to provide feature.