How the hell do you think they got them on there? Just like the old days when drop bars were threaded through stem clamps, and when shifters are put on riser bars on MTBs, and shifters are put on traditional swept-back bars in Europe. Sometimes I wonder if there are schools for serial idiots.
Well it wasn't obvious how to get those shifters on there considering cutting a handlebar in half then welding it back together sounds like a dangerous and ridiculous idea.