orderConnector = new OrderConnector(this, mAccount, null);
    orderConnector.addOnOrderChangedListener(new TestOrderChangeListener());
    orderConnector.connect();

// ...

    private class TestOrderChangeListener implements OrderConnector.OnOrderUpdateListener2 {
    // more overrides...

        @Override
        public void onPaymentProcessed(String orderId, String paymentId) {
            Log.e(TAG, "Payment processed:" + orderId + " " + paymentId);
        }
    }