centralManagerDidUpdateState.swift

func centralManagerDidUpdateState(_ central: CBCentralManager) {
           switch central.state {
           case .unauthorized:
               switch central.authorization {
               case .allowedAlways:
               case .denied:
               case .restricted:
               case .notDetermined:
           }
           case .unknown:
           case .unsupported:
           case .poweredOn:
               self.centralManager?.scanForPeripherals(withServices: nil, options: [CBCentralManagerScanOptionAllowDuplicatesKey:true])
           case .poweredOff:
           case .resetting:
           @unknown default:
           }
 }