docs: private void handlePostAuthReturn() {
          final Uri intentUri = getIntent().getData();
          if (intentUri != null) {
              if ("stripe".equals(intentUri.getScheme()) &&
                      "payment-auth-return".equals(intentUri.getHost())) {
                  final String paymentIntentClientSecret =
                          intentUri.getQueryParameter("payment_intent_client_secret");
                  if (paymentIntentClientSecret != null) {
                      final Stripe stripe = new Stripe(getApplicationContext(),
                              PaymentConfiguration.getInstance().getPublishableKey());
                      final PaymentIntentParams paymentIntentParams = PaymentIntentParams
                              .createRetrievePaymentIntentParams(paymentIntentClientSecret);
                      mCompositeDisposable.add(Observable
                              .fromCallable(() ->
                                      stripe.retrievePaymentIntentSynchronous(paymentIntentParams,
                                              PaymentConfiguration.getInstance().getPublishableKey()))
                              .subscribeOn(Schedulers.io())
                              .observeOn(AndroidSchedulers.mainThread())
                              .subscribe((paymentIntent -> {
                                  if (paymentIntent != null) {
                                      handleRetrievedPaymentIntent(paymentIntent);
                                  }
                              }))
                      );
                  }
              }
          }
      }