/// <summary>
 /// Quick helper around WhenStatusChanged().Where(x => x == ConnectionStatus.Disconnected)
 /// </summary>
 /// <param name="peripheral"></param>
 /// <returns></returns>
 public static IObservable <IPeripheral> WhenDisconnected(this IPeripheral peripheral) =>
 peripheral
 .WhenStatusChanged()
 .Where(x => x == ConnectionState.Disconnected)
 .Select(_ => peripheral);