SEATTLE – As a new father, UFC flyweight titleholder Demetrious Johnson (18-2-1 MMA, 6-1-1 UFC) is all about cashing the biggest checks possible, and he thinks a superfight with either of the UFC’s two current bantamweight champions could provide exactly that. However, he believes there are still plenty of challenges at flyweight, as well. “I’ve beat the best of the best in the flyweight division, and there are still up-and-comers in there,” Johnson said at Saturday night’s post-UFC on FOX 8 press conference in Seattle. “I know there’s some key matchups coming up pretty soon. … There are still a couple of flyweights out there that I haven’t fought yet, and I wouldn’t mind fighting them.