FILE - This is a Tuesday, Jan. 2, 2018 file photo of Belinda Bencic, left, and Roger Federer of Switzerland as they clap hands during their mixed doubles match against Karen Khachanov and Anastasia Pavlyuchenkova of Russia at the Hopman Cup tennis tournament in Perth, Australia. Roger Federer and Belinda Bencic advanced Switzerland into the Hopman Cup final with straight-set singles victories over their American opponents. (Tony McDonough/AAP Image, File via AP)