post(new Route("/webhooks") {
  @Override
  public Object handle(spark.Request request, Response response) {
    WebhookNotification webhookNotification = gateway.webhookNotification().parse(
      request.queryParams("bt_signature"),
      request.queryParams("bt_payload")
    );

    // Example values for webhook notification properties
    System.out.println(webhookNotification.getKind()); // "subscription_went_past_due"
    System.out.println(webhookNotification.getTimestamp()); // "Sun Jan 1 00:00:00 UTC 2012"

    response.status(200);
    return("");
  }
});