NotificationCenter.default.addObserver(forName: .GCControllerDidConnect, object: nil, queue: .main) { (note) in
        if let controller = note.object as? GCController {
            if controller.playerIndex != .indexUnset {
                print("setting up controller (controller.playerIndex.rawValue)")
                self.setupController(controller)
                return
            }

            var availableIndexes = [0, 1, 2, 3]
            for connectedController in GCController.controllers() {
                if let occupiedIndex = availableIndexes.index(of: connectedController.playerIndex.rawValue) {
                    availableIndexes.remove(at: occupiedIndex)
                }
            }
            if !availableIndexes.isEmpty {
                controller.playerIndex = GCControllerPlayerIndex(rawValue: availableIndexes.first!)!
                print("setting up controller (controller.playerIndex.rawValue)")
                self.setupController(controller)
            }

        }
    }

setting up controller 0
setting up controller 1