return None

    def _create_credentials_fetcher(self):
        method = self.METHOD

        def fetch_credentials():
            # HTTP headers are case insensitive filter out
            # all duplicate headers and pick one.
            headers = {}
            headers['content-type'] = 'application/x-www-form-urlencoded'
            headers['authorization'] = urllib3.make_headers(

- Fixed a regression in default configurations, which enabled PodDisruptionConditions by default, 
  that prevented the control plane's pod garbage collector from deleting pods that contained duplicated field keys (env. variables with repeated keys or container ports). ([#121380](https://github.com/kubernetes/kubernetes/pull/121380), [@mimowo](https://github.com/mimowo)) [SIG Apps, Auth, Scheduling and Testing]

        Objects.requireNonNull(extensionRealm, "extensionRealm cannot be null");

        if (cache.containsKey(key)) {
            throw new IllegalStateException("Duplicate extension realm for extension " + key);
        }

        CacheRecord record = new CacheRecord(extensionRealm, extensionDescriptor, artifacts);

        cache.put(key, record);

        return record;

    testers.add(SetHashCodeTester.class);
    testers.add(SetEqualsTester.class);
    testers.add(SetRemoveTester.class);
    // SetRemoveAllTester doesn't exist because, Sets not permitting
    // duplicate elements, there are no tests for Set.removeAll() that aren't
    // covered by CollectionRemoveAllTester.
    return testers;
  }

  @Override
  protected List<TestSuite> createDerivedSuites(

    //
    // 8) Create ReactorReader with the getProjectMap( projects ). NOTE that getProjectMap(projects) is the code that
    // checks for duplicate projects definitions in the build. Ideally this type of duplicate checking should be
    // part of getting the reactor projects in 6). The duplicate checking is conflated with getProjectMap(projects).
    //
    // 9) Execute AbstractLifecycleParticipant.afterProjectsRead(session)
    //

    }

    private static String parse(String rule, Set<String> dup) {
        String[] values = CSVUtil.parse(rule);
        if (dup.add(values[0]) == false) {
            throw new IllegalArgumentException("Found duplicate term [" + values[0] + "] in user dictionary.");
        }
        return rule;
    }

    public static UserDictionary getUserDictionary(Environment env, Settings settings) {

import java.util.ArrayDeque
import java.util.Deque
import javax.net.ssl.SSLPeerUnverifiedException

/**
 * A certificate chain cleaner that uses a set of trusted root certificates to build the trusted
 * chain. This class duplicates the clean chain building performed during the TLS handshake. We
 * prefer other mechanisms where they exist, such as with
 * [okhttp3.internal.platform.AndroidPlatform.AndroidCertificateChainCleaner].
 *

                <project xmlns="http://maven.apache.org/POM/4.0.0">
                    <modelVersion>4.0.0</modelVersion>
                    <groupId>com.example</groupId>
                    <artifactId>duplicate-project</artifactId>
                    <version>1.0.0</version>
                </project>
                """;

            Document doc1 = Document.of(pomXml);
            Document doc2 = Document.of(pomXml);

    int NT_STATUS_PIPE_LISTENING = 0xC00000b3;
    /** The file that was specified is a directory */
    int NT_STATUS_FILE_IS_A_DIRECTORY = 0xC00000ba;
    /** A duplicate name exists on the network */
    int NT_STATUS_DUPLICATE_NAME = 0xC00000bd;
    /** The specified network name is no longer available */
    int NT_STATUS_NETWORK_NAME_DELETED = 0xC00000c9;

    for (Field field : httpHeadersFields()) {
      assertEquals(
          upperToHttpHeaderName(field.getName(), specialCases, uppercaseAcronyms), field.get(null));
    }
  }

  // Tests that there are no duplicate HTTP header names
  public void testNoDuplicateFields() throws Exception {
    ImmutableList.Builder<String> httpHeaders = ImmutableList.builder();
    for (Field field : httpHeadersFields()) {