/// <summary>
/// Sends the notification(s).
/// </summary>
/// <param name="activity"></param>
/// <param name="state">Should contain the notification as JSON string.
/// We store it to the state in PrepareAsync method (see the return value).</param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
protected override async Task PostAsync(IActivity activity, string state, CancellationToken cancellationToken)
{
await NotificationsManager.SendNotificationAsync(state);
await _dialogTask.PollAsync(cancellationToken);
}