KEY WEST, Fla.- Battle-tested Bahamian heavyweight Sherman “Tank” Williams (36-13-2, 19 KOs) is returning to Germany to spar three weeks with world heavyweight champion Wladimir Klitschko (61-3, 51 KOs) and then fight highly-touted New Zealand prospect “Explosive” Joseph Parker (7-0, 6 KOs) on April 26 in Oberhauser, Germany.