InAppPurchase_code8.java

private void consumeDownloadPurchase(Purchase purchase) {
    mHelper.consumeAsync(purchase, new IabHelper.OnConsumeFinishedListener() {
        @Override
        public void onConsumeFinished(Purchase purchase, IabResult result) {
            if (result.isFailure()) {
                Toast.makeText(DetailActivity.this, R.string.purchasing_error, Toast.LENGTH_SHORT).show();
                return;
            }
            startDownloading();
        }
    });
}