com.google.common.io.BaseEncoding Java Examples

/** Create a secure JWT token for the given userId. */
public String createFirebaseToken(Game game, String userId) {
  final AppIdentityService appIdentity = AppIdentityServiceFactory.getAppIdentityService();
  final BaseEncoding base64 = BaseEncoding.base64();

  String header = base64.encode("{\"typ\":\"JWT\",\"alg\":\"RS256\"}".getBytes());

  // Construct the claim
  String channelKey = game.getChannelKey(userId);
  String clientEmail = appIdentity.getServiceAccountName();
  long epochTime = System.currentTimeMillis() / 1000;
  long expire = epochTime + 60 * 60; // an hour from now

  Map<String, Object> claims = new HashMap<String, Object>();
  claims.put("iss", clientEmail);
  claims.put("sub", clientEmail);
  claims.put("aud", IDENTITY_ENDPOINT);
  claims.put("uid", channelKey);
  claims.put("iat", epochTime);
  claims.put("exp", expire);

  String payload = base64.encode(new Gson().toJson(claims).getBytes());
  String toSign = String.format("%s.%s", header, payload);
  AppIdentityService.SigningResult result = appIdentity.signForApp(toSign.getBytes());
  return String.format("%s.%s", toSign, base64.encode(result.getSignature()));
}
 

@Override
public SfsRequest call(SfsRequest httpServerRequest) {
    MultiMap headers = httpServerRequest.headers();

    String value = headers.get(headerName);
    if (value != null) {
        boolean failed = false;
        BaseEncoding baseEncoding = base64();
        try {
            byte[] decoded = baseEncoding.decode(value);
            if (decoded == null || !value.equals(baseEncoding.encode(decoded))) {
                failed = true;
            }
        } catch (Throwable e) {
            // do nothing
        }
        if (failed) {
            JsonObject jsonObject = new JsonObject()
                    .put("message", format("%s must be Base64 encoded", headerName));

            throw new HttpRequestValidationException(HTTP_BAD_REQUEST, jsonObject);
        }
    }
    return httpServerRequest;
}
 

private void verifyAddressSize(byte[] address) {
// CHECKSTYLE:ON
    int addressLength = address.length;
    switch (addressFamily) {
    case AF_UNSPEC:
    case AF_INET:
    case AF_INET6:
        if (addressLength != addressFamily.getAddressSize()) {
            throw new InvalidHeaderException("For the address family " + addressFamily +
                    " expected address size " + addressFamily.getAddressSize() + " but got "
                    + addressLength + " for the address "
                    + BaseEncoding.base16().lowerCase().encode(address));
        }
        break;
    case AF_UNIX:
        // Unix address can be smaller than the reserved space
        if (addressLength > addressFamily.getAddressSize()
            || addressLength == 0) {
            throw new InvalidHeaderException("Invalid size " + addressLength +
                    " of the Unix address "
                    + BaseEncoding.base16().lowerCase().encode(address));
        }
        break;
    }
}
 

private String getCertificateThumbprint(String pfxPath, String password) {
    try {
        InputStream inStream = new FileInputStream(pfxPath);

        KeyStore ks = KeyStore.getInstance("PKCS12");
        ks.load(inStream, password.toCharArray());

        String alias = ks.aliases().nextElement();
        X509Certificate certificate = (X509Certificate) ks.getCertificate(alias);
        inStream.close();
        MessageDigest sha = MessageDigest.getInstance("SHA-1");
        return BaseEncoding.base16().encode(sha.digest(certificate.getEncoded()));
    } catch (KeyStoreException | CertificateException | NoSuchAlgorithmException | IOException ex) {
        throw new RuntimeException(ex);
    }
}
 

private String build(Platform cloudPlatform, byte[] cbSshKeyDer, String sshUser,
        PlatformParameters params, String saltBootPassword, String cbCert, CcmParameters ccmParameters, ProxyConfig proxyConfig) {
    Map<String, Object> model = new HashMap<>();
    model.put("cloudPlatform", cloudPlatform.value());
    model.put("platformDiskPrefix", params.scriptParams().getDiskPrefix());
    model.put("platformDiskStartLabel", params.scriptParams().getStartLabel());
    model.put("gateway", true);
    model.put("signaturePublicKey", BaseEncoding.base64().encode(cbSshKeyDer));
    model.put("sshUser", sshUser);
    model.put("customUserData", userDataBuilderParams.getCustomData());
    model.put("saltBootPassword", saltBootPassword);
    model.put("cbCert", cbCert);
    CcmParameters.addToTemplateModel(ccmParameters, model);
    extendModelWithProxyParams(proxyConfig, model);
    return build(model);
}
 

/**
 * Transform HTTP/2-compliant headers to the raw serialized format which can be deserialized by
 * metadata marshallers. It decodes the Base64-encoded binary headers.
 *
 * <p>Warning: This function may partially modify the headers in place by modifying the input
 * array (but not modifying any single byte), so the input reference {@code http2Headers} can not
 * be used again.
 *
 * @param http2Headers the interleaved keys and values of HTTP/2-compliant headers
 * @return the interleaved keys and values in the raw serialized format
 */
@CheckReturnValue
public static byte[][] toRawSerializedHeaders(byte[][] http2Headers) {
  for (int i = 0; i < http2Headers.length; i += 2) {
    byte[] key = http2Headers[i];
    byte[] value = http2Headers[i + 1];
    if (endsWith(key, binaryHeaderSuffixBytes)) {
      // Binary header
      for (int idx = 0; idx < value.length; idx++) {
        if (value[idx] == (byte) ',') {
          return serializeHeadersWithCommasInBin(http2Headers, i);
        }
      }
      byte[] decodedVal = BaseEncoding.base64().decode(new String(value, US_ASCII));
      http2Headers[i + 1] = decodedVal;
    } else {
      // Non-binary header
      // Nothing to do, the value is already in the right place.
    }
  }
  return http2Headers;
}
 

/**
 * Returns the base64-encoded string representation of this DuoCookie. The
 * format used is identical to that required by the Duo service: the
 * username, integration key, and expiration timestamp separated by pipe
 * symbols ("|") and encoded with base64.
 *
 * @return
 *     The base64-encoded string representation of this DuoCookie.
 */
@Override
public String toString() {

    try {

        // Separate each cookie field with pipe symbols
        String data = username + "|" + integrationKey + "|" + expires;

        // Encode resulting cookie string with base64
        return BaseEncoding.base64().encode(data.getBytes("UTF-8"));

    }

    // Throw hard errors if standard pieces of Java are missing
    catch (UnsupportedEncodingException e) {
        throw new UnsupportedOperationException("Unexpected lack of UTF-8 support.", e);
    }

}
 

@Test
public void testRolesMissing() throws Exception {



    Settings settings = Settings.builder()
            .put("signing_key", BaseEncoding.base64().encode(secretKey))
            .put("roles_key", "roles")
            .build();

    String jwsToken = Jwts.builder()
            .setSubject("Leonard McCoy")
            .signWith(SignatureAlgorithm.HS512, secretKey).compact();

    HTTPJwtAuthenticator jwtAuth = new HTTPJwtAuthenticator(settings, null);
    Map<String, String> headers = new HashMap<String, String>();
    headers.put("Authorization", jwsToken);

    AuthCredentials creds = jwtAuth.extractCredentials(new FakeRestRequest(headers, new HashMap<String, String>()), null);
    Assert.assertNotNull(creds);
    Assert.assertEquals("Leonard McCoy", creds.getUsername());
    Assert.assertEquals(0, creds.getBackendRoles().size());
}
 

/**
 * When the test is run, this method reads the local fixtures resource and performs a checksum on the file contents to
 * ensure the integrity of the file and compares it with the expected {@code stream.packetFixtures.checksum} value in
 * the properties configuration located at {@code fixtures.properties}.
 *
 * <p>This test is present to ensure that in case the file is updated locally, we also update the corresponding
 * checksum of the file.</p>
 *
 * @return {@code false} if the fixtures have changed locally, else {@code true}.
 */
private static boolean checkLocalFixtureFileState() {
  Properties properties = readProperties();
  String expectedCheckSum = (String) properties.get("stream.packetFixtures.checksum");
  String fileName = (String) properties.get("stream.packetFixtures.fileName");

  try {
    Path path = Paths.get(StreamPacketFixturesTest.class.getClassLoader().getResource(fileName).toURI());
    byte[] buffer = Files.readAllBytes(path);
    Objects.requireNonNull(buffer);
    String computedCheckSum = BaseEncoding.base16().encode(checksum(buffer)).toLowerCase();
    return computedCheckSum.equals(expectedCheckSum);
  } catch (URISyntaxException | IOException e) {
    e.printStackTrace();
  }

  return false;
}
 

@Test
public void shouldAddAuthenticationHeader() throws IOException, URISyntaxException {

  Capture<String> capturedAuth = EasyMock.newCapture();

  HttpURLConnection connection = EasyMock.createNiceMock(HttpsURLConnection.class);
  EasyMock.expect(connection.getResponseCode()).andStubReturn(HTTP_FORBIDDEN);
  connection.addRequestProperty(eq("Authorization"), capture(capturedAuth));
  EasyMock.expectLastCall();
  EasyMock.replay(connection);

  HttpDownloader downloader = getDownloader(connection);
  PasswordAuthentication credentials = new PasswordAuthentication("foo", "bar".toCharArray());
  boolean result =
      downloader.fetch(
          eventBus, new URI("https://example.com"), Optional.of(credentials), neverUsed);
  assertFalse(result);

  EasyMock.verify(connection);

  Matcher m = Pattern.compile("^Basic (.*)$").matcher(capturedAuth.getValue());
  assertTrue(m.matches());
  assertEquals(
      "foo:bar", new String(BaseEncoding.base64().decode(m.group(1)), StandardCharsets.UTF_8));
}
 

/**
 * Calculates MinHash value.
 * 
 * @param analyzer analyzer to parse a text
 * @param text a target text
 * @return MinHash value
 * @throws IOException
 */
public static byte[] calculate(final Analyzer analyzer, final String text)
        throws IOException {
    byte[] value = null;
    try (TokenStream stream = analyzer.tokenStream("minhash", text)) {
        final CharTermAttribute termAtt = stream
                .addAttribute(CharTermAttribute.class);
        stream.reset();
        if (stream.incrementToken()) {
            final String minhashValue = termAtt.toString();
            value = BaseEncoding.base64().decode(minhashValue);
        }
        stream.end();
    }
    return value;
}
 

@Test
public void testPullSingle() throws IOException, ExecutionException, InterruptedException {
  // Create topic and subscription
  pubsub.createTopic(PROJECT, TOPIC).get();
  pubsub.createSubscription(PROJECT, SUBSCRIPTION, TOPIC).get();

  // Publish a message
  final String data = BaseEncoding.base64().encode("hello world".getBytes("UTF-8"));
  final Message message = Message.of(data);
  final List<String> ids = pubsub.publish(PROJECT, TOPIC, message).get();
  final String id = ids.get(0);
  final List<ReceivedMessage> response = pubsub.pull(PROJECT, SUBSCRIPTION, false).get();

  // Verify received message
  assertThat(response.size(), is(1));
  assertThat(response.get(0).message().data(), is(data));
  assertThat(response.get(0).message().messageId().get(), is(id));
  assertThat(response.get(0).message().publishTime().get(), is(notNullValue()));
  assertThat(response.get(0).ackId(), not(isEmptyOrNullString()));

  // Modify ack deadline
  pubsub.modifyAckDeadline(PROJECT, SUBSCRIPTION, 30, response.get(0).ackId()).get();

  // Ack message
  pubsub.acknowledge(PROJECT, SUBSCRIPTION, response.get(0).ackId()).get();
}
 

@Test
public void testExpressionConstantFolding()
{
    FunctionCall fromHex = new FunctionCallBuilder(metadata)
            .setName(QualifiedName.of("from_hex"))
            .addArgument(VARCHAR, stringLiteral("123456"))
            .build();
    Expression originalExpression = comparison(GREATER_THAN, C_VARBINARY.toSymbolReference(), fromHex);
    ExtractionResult result = fromPredicate(originalExpression);
    assertEquals(result.getRemainingExpression(), TRUE_LITERAL);
    Slice value = Slices.wrappedBuffer(BaseEncoding.base16().decode("123456"));
    assertEquals(result.getTupleDomain(), withColumnDomains(ImmutableMap.of(C_VARBINARY, Domain.create(ValueSet.ofRanges(Range.greaterThan(VARBINARY, value)), false))));

    Expression expression = toPredicate(result.getTupleDomain());
    assertEquals(expression, comparison(GREATER_THAN, C_VARBINARY.toSymbolReference(), varbinaryLiteral(value)));
}
 

/**
 * @param data
 * @throws ResponseException
 */
public AuthenticatorAttestationResponse(JsonElement data) throws ResponseException {
  Gson gson = new Gson();
  AttestationResponseJson parsedObject = gson.fromJson(data, AttestationResponseJson.class);

  clientDataBytes = BaseEncoding.base64().decode(parsedObject.clientDataJSON);
  byte[] attestationObject = BaseEncoding.base64().decode(parsedObject.attestationObject);

  try {
    decodedObject = AttestationObject.decode(attestationObject);
  } catch (CborException e) {
    throw new ResponseException("Cannot decode attestation object");
  }

  clientData = gson.fromJson(new String(clientDataBytes, StandardCharsets.UTF_8),
      CollectedClientData.class);
  transports = parsedObject.transports;
}
 

@Test
@Description("Verfies that artifacts with equal binary content are only stored once.")
public void storeSameArtifactMultipleTimes() throws NoSuchAlgorithmException, IOException {

    final byte[] bytes = new byte[128];
    new Random().nextBytes(bytes);

    final MessageDigest mdSHA1 = MessageDigest.getInstance("SHA1");
    final MessageDigest mdSHA256 = MessageDigest.getInstance("SHA-256");
    final MessageDigest mdMD5 = MessageDigest.getInstance("MD5");
    final DbArtifactHash hash = new DbArtifactHash(BaseEncoding.base16().lowerCase().encode(mdSHA1.digest(bytes)),
            BaseEncoding.base16().lowerCase().encode(mdMD5.digest(bytes)),
            BaseEncoding.base16().lowerCase().encode(mdSHA256.digest(bytes)));

    final AbstractDbArtifact artifact1 = storeArtifact(TENANT, "file1.txt", new ByteArrayInputStream(bytes), mdSHA1,
            mdMD5, hash);
    final AbstractDbArtifact artifact2 = storeArtifact(TENANT, "file2.bla", new ByteArrayInputStream(bytes), mdSHA1,
            mdMD5, hash);
    assertThat(artifact1.getArtifactId()).isEqualTo(artifact2.getArtifactId());

}
 

public void testReturnRawInputStream_True() throws Exception {
  HttpTransport transport = new MockHttpTransport() {
    @Override
    public LowLevelHttpRequest buildRequest(final String method, final String url) {
      return new MockLowLevelHttpRequest() {
        @Override
        public LowLevelHttpResponse execute() {
          return new MockLowLevelHttpResponse().setContentEncoding("gzip").setContent(new ByteArrayInputStream(
              BaseEncoding.base64()
                  .decode("H4sIAAAAAAAAAPNIzcnJV3DPz0/PSVVwzskvTVEILskvSkxPVQQA/LySchsAAAA=")));
        }
      };
    }
  };
  MockGoogleClient client = new MockGoogleClient.Builder(transport, ROOT_URL, SERVICE_PATH,
      JSON_OBJECT_PARSER, null).setApplicationName(
      "Test Application").build();
  MockGoogleClientRequest<String> request = new MockGoogleClientRequest<String>(
      client, HttpMethods.GET, URI_TEMPLATE, null, String.class);
  request.setReturnRawInputStream(true);
  InputStream inputStream = request.executeAsInputStream();
  // The response will not be wrapped due to setReturnRawInputStream(true)
  assertTrue(inputStream instanceof ByteArrayInputStream);
}
 

@Override
public Response intercept(Chain chain) throws IOException {
    String auth = credentials.getUserName() + ":" + credentials.getPassword();
    auth = BaseEncoding.base64().encode(auth.getBytes("UTF8"));
    Request newRequest = chain.request().newBuilder()
            .header("Authorization", "Basic " + auth)
            .build();
    return chain.proceed(newRequest);
}
 

@Override
public void writeHeaders(Metadata metadata, byte[] payload) {
  startCallback.run();

  BidirectionalStreamCallback callback = new BidirectionalStreamCallback();
  String path = url;
  if (payload != null) {
    path += "?" + BaseEncoding.base64().encode(payload);
  }
  BidirectionalStream.Builder builder =
      streamFactory.newBidirectionalStreamBuilder(path, callback, executor);
  if (payload != null) {
    builder.setHttpMethod("GET");
  } else if (idempotent) {
    builder.setHttpMethod("PUT");
  }
  if (delayRequestHeader) {
    builder.delayRequestHeadersUntilFirstFlush(true);
  }
  if (annotation != null) {
    ((ExperimentalBidirectionalStream.Builder) builder).addRequestAnnotation(annotation);
  }
  if (annotations != null) {
    for (Object o : annotations) {
      ((ExperimentalBidirectionalStream.Builder) builder).addRequestAnnotation(o);
    }
  }
  setGrpcHeaders(builder);
  stream = builder.build();
  stream.start();
}
 

/**
 * Returns true if the provided String _could_ be encrypted credentials, even if it can't be decrypted
 * by a specific instance.
 */
public static boolean isPotentiallyEncryptedString(String string) {
    checkNotNull(string, "string");

    // String is base64 encoded
    byte[] encryptedBytes;
    try {
        encryptedBytes = BaseEncoding.base64().omitPadding().decode(string);
    } catch (IllegalArgumentException e) {
        return false;
    }

    return isPotentiallyEncryptedBytes(encryptedBytes);
}
 

@Override
public String encrypt(String data) {
  try {
    Cipher cipher;
    switch (transformation) {
      case AES_CBC_NOPADDING:
        cipher = Cipher.getInstance("AES/CBC/NoPadding");
        cipher.init(Cipher.ENCRYPT_MODE, key, generateIv(cipher));
        break;
      case RSA_ECB_PKCS1:
        cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key);        
        break;
      default:
        throw new AssertionError("How could this happen...");
    }
    // we use a salt the size of the first block
    // so that we don't need to know IV for AES/CBC
    byte[] salt = new byte[cipher.getBlockSize()];
    SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
    random.nextBytes(salt);
    cipher.update(salt);
    byte[] encrypted = cipher.doFinal(data.getBytes(Charsets.UTF_8));
    return BaseEncoding.base64Url().encode(encrypted);
  } catch (BadPaddingException
      | IllegalBlockSizeException
      | InvalidAlgorithmParameterException
      | InvalidKeyException
      | NoSuchAlgorithmException
      | NoSuchPaddingException e) {
    monitor.severe(() -> format("Exception encrypting data, length: %s", data.length()), e);
    throw new RuntimeException(e);
  }
}
 

public String getSignResponseFromServer(AuthenticatorAssertionResponse response) {
    Log.d(TAG, "getSignResponseFromServer");
    try {
        if (fido2Service == null) {
            return null;
        }
        JSONObject responseJson = new JSONObject();
        String clientDataJSON = new String(response.getClientDataJSON(), "UTF-8");
        String authenticatorData = BaseEncoding.base64().encode(response.getAuthenticatorData());
        String credentialId = BaseEncoding.base64Url().encode(response.getKeyHandle());
        String signature = BaseEncoding.base64().encode(response.getSignature());
        responseJson.put(KEY_CLIENT_DATA_JSON, clientDataJSON);
        responseJson.put(KEY_AUTHENTICATOR_DATA, authenticatorData);
        responseJson.put(KEY_CREDENTIAL_ID, credentialId);
        responseJson.put(KEY_SIGNATURE, signature);

        // insert sessionId for the authenticated credential ID into result data in JSON format,
        // and pass it back to server.
        String sessionId = sessionIds.get(BaseEncoding.base64Url().encode(response.getKeyHandle()));
        responseJson.put(KEY_SESSION_ID, sessionId);

        List<String> signResponseContent =
                fido2Service.processSignResponse(responseJson.toString()).execute().getItems();
        if (signResponseContent == null || signResponseContent.isEmpty()) {
            Log.i(TAG, "signResponseContent is null or empty");
        } else {
            Log.i(TAG, "signResponseContent " + signResponseContent.get(0));
            JSONObject credential = new JSONObject(signResponseContent.get(0));
            // return string value of the authenticated credential
            return credential.toString();
        }

    } catch (IOException | JSONException e) {
        Log.e(TAG, "Error processing sign response", e);
    }

    return null;
}
 

protected String registryAuth(@Nonnull AuthConfig authConfig) {
    try {
        return BaseEncoding.base64Url().encode(dockerClientConfig.getObjectMapper().writeValueAsString(authConfig).getBytes());
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}
 

/**
 * Convert to a @{link com.google.devtools.build.lib.skyframe.FileValue} to a String appropriate
 * for placing in a repository marker file.
 *
 * @param fileValue The value to convert. It must correspond to a regular file.
 */
public static String fileValueToMarkerValue(FileValue fileValue) throws IOException {
  Preconditions.checkArgument(fileValue.isFile() && !fileValue.isSpecialFile());
  // Return the file content digest in hex. fileValue may or may not have the digest available.
  byte[] digest = ((RegularFileStateValue) fileValue.realFileStateValue()).getDigest();
  if (digest == null) {
    digest = fileValue.realRootedPath().asPath().getDigest();
  }
  return BaseEncoding.base16().lowerCase().encode(digest);
}
 

@Test
public void test_base64String() {
  byte[] bytes = new byte[] {65, 66, 67, 99};
  @SuppressWarnings("deprecation")
  String base64 = BaseEncoding.base64().encode(bytes);
  ArrayByteSource test = ArrayByteSource.copyOf(bytes);
  assertThat(test.toBase64String()).isEqualTo(base64);
  ArrayByteSource roundtrip = ArrayByteSource.fromBase64(base64);
  assertThat(roundtrip).isEqualTo(test);
  assertThat(test.toBase64String()).isEqualTo(test.toBase64().readUtf8());
}
 

PasswordCredentialImpl(String name, HasCredential<?> parent) {
    super(new PasswordCredentialInner()
            .withCustomKeyIdentifier(BaseEncoding.base64().encode(name.getBytes()))
            .withStartDate(DateTime.now())
            .withEndDate(DateTime.now().plusYears(1)));
    this.name = name;
    this.parent = parent;
}
 

/** Creates a SHA-512 hash of the given String. */
@VisibleForTesting
static String sha512(final String input) {
  try {
    return BaseEncoding.base16()
        .encode(MessageDigest.getInstance(SHA_512).digest(input.getBytes(StandardCharsets.UTF_8)))
        .toLowerCase();
  } catch (final NoSuchAlgorithmException e) {
    throw new IllegalStateException(SHA_512 + " is not supported!", e);
  }
}
 

private void setClientKeys(SecurityConfig securityConfig, KeyPair identity, KeyPair signKey) {
    X509Certificate cert = PkiUtil.cert(identity, "cloudbreak", signKey);

    String clientPrivateKey = PkiUtil.convert(identity.getPrivate());
    String clientCert = PkiUtil.convert(cert);

    securityConfig.setClientKey(BaseEncoding.base64().encode(clientPrivateKey.getBytes()));
    securityConfig.setClientCert(BaseEncoding.base64().encode(clientCert.getBytes()));
}
 

public static void printHybridEncryptionData(KeysetHandle privateKeysetHandle, KeysetHandle publicKeysetHandle, String initialText, byte[] cipherText, byte[] plainText) {
    log.info("initial text: {}", initialText);
    log.info("cipher text: {}", BaseEncoding.base16().encode(cipherText));
    log.info("plain text: {}", new String(plainText, StandardCharsets.UTF_8));

    printKeyset("private key set data", privateKeysetHandle);
    printKeyset("public key set data", publicKeysetHandle);
}
 

@Override
public Object apply(WarpScriptStack stack) throws WarpScriptException {
  Object o = stack.pop();
  
  if (!(o instanceof String)) {
    throw new WarpScriptException(getName() + " operates on a String.");
  }
  
  stack.push(new String(Hex.encode(BaseEncoding.base64().decode(o.toString())), StandardCharsets.UTF_8));
  
  return stack;
}
 

@Override
public String getBasicAuth() {
    final String base64UserPassCombination = bufferedHttpOutputMessage.getHeaders().get(HttpHeaders.AUTHORIZATION);
    if (base64UserPassCombination != null && base64UserPassCombination.startsWith("Basic")) {
        return new String(BaseEncoding.base64().decode(base64UserPassCombination), Charsets.UTF_8).replaceFirst("Basic", "").trim();
    } else {
        return null;
    }
}