### Question:
Gateway { String inputStreamToString(InputStream is) throws IOException { BufferedReader rd = new BufferedReader(new InputStreamReader(is)); StringBuilder total = new StringBuilder(); String line; while ((line = rd.readLine()) != null) { total.append(line); } return total.toString(); } Gateway(); String getMerchantId(); Gateway setMerchantId(String merchantId); Region getRegion(); Gateway setRegion(Region region); void updateSession(String sessionId, String apiVersion, GatewayMap payload, GatewayCallback callback); Single<GatewayMap> updateSession(String sessionId, String apiVersion, GatewayMap payload); static void start3DSecureActivity(Activity activity, String html); static void start3DSecureActivity(Activity activity, String html, String title); static boolean handle3DSecureResult(int requestCode, int resultCode, Intent data, Gateway3DSecureCallback callback); static void requestGooglePayData(PaymentsClient paymentsClient, PaymentDataRequest request, Activity activity); static boolean handleGooglePayResult(int requestCode, int resultCode, Intent data, GatewayGooglePayCallback callback);  }### Answer:
@Test public void testInputStreamToStringWorksAsExpected() { String expectedResult = "here is some string data"; InputStream testInputStream = new StringInputStream(expectedResult); try { String result = gateway.inputStreamToString(testInputStream); assertEquals(expectedResult, result); } catch (IOException e) { fail(e.getMessage()); } }