virtual [TFuture](API\Runtime\Core\Async\TFuture)< [TOnlineResult](API\Plugins\OnlineServicesInterface\Online\TOnlineResult)< [FLeaveSession](API\Plugins\OnlineServicesInterface\Online\FLeaveSession) > > LeaveSessionImpl ( const [FLeaveSession::Params](API\Plugins\OnlineServicesInterface\Online\FLeaveSession\Params) & Params )