)
        else:
            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(

                .map(s -> s.substring(1))
                .toArray(n -> new String[n]));
    }

    @Override
    public String[] getGroupNames() {
        final FessConfig fessConfig = ComponentUtil.getFessConfig();
        return stream(getPermissions()).get(stream -> stream.filter(s -> s.startsWith(fessConfig.getRoleSearchGroupPrefix()))

            final RESULT result = entityType.newInstance();
            result.setName(DfTypeUtil.toString(source.get("name")));
            result.setAttributes(source.entrySet()
                    .stream()
                    .filter(e -> !"name".equals(e.getKey()))
                    .map(e -> new Pair<>(e.getKey(), (String) e.getValue()))
                    .collect(Collectors.toMap(Pair::getFirst, Pair::getSecond)));
            return result;

    public SimpleLookup(List<Object> objects) {
        this.objects = objects;
    }

    @Override
    public <T> T lookup(Class<T> type) {
        return objects.stream()
                .filter(type::isInstance)
                .map(type::cast)
                .findAny()
                .orElseThrow(() -> new LookupException("No service of type " + type));
    }

    @Override

 */
@Deprecated(since = "4.0.0")
public interface Source {

    /**
     * Gets a byte stream to the source contents. Closing the returned stream is the responsibility of the caller.
     *
     * @return A byte stream to the source contents, never {@code null}.
     * @throws IOException in case of IO issue
     */
    InputStream getInputStream() throws IOException;

    /**

     *
     * @param keyPattern The pattern to filter environment variable keys.
     * @return A map of filtered environment variables.
     */
    public Map<String, String> getFilteredEnvMap(final String keyPattern) {
        final Pattern pattern = Pattern.compile(keyPattern);
        return getEnvMap().entrySet().stream().filter(e -> {
            final String key = e.getKey();

 */
enum BloomFilterStrategies implements BloomFilter.Strategy {
  /**
   * See "Less Hashing, Same Performance: Building a Better Bloom Filter" by Adam Kirsch and Michael
   * Mitzenmacher. The paper argues that this trick doesn't significantly deteriorate the
   * performance of a Bloom filter (yet only needs two 32bit hash functions).
   */
  MURMUR128_MITZ_32() {
    @Override
    public <T extends @Nullable Object> boolean put(

  static <E extends @Nullable Object> Collection<E> filterCollection(
      Collection<E> collection, Predicate<? super E> predicate) {
    if (collection instanceof Set) {
      return Sets.filter((Set<E>) collection, predicate);
    } else {
      return Collections2.filter(collection, predicate);
    }
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    return asMap().get(key) != null;
  }

  @Override

            return DirectoryChangeType.DIRECTORY_RENAMED;
        default:
            return DirectoryChangeType.ATTRIBUTES_CHANGED;
        }
    }

    /**
     * Get notification filter flags
     *
     * @return filter flags for change notifications
     */
    public int getNotificationFilter() {

    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

But most importantly:

* It will **limit and filter** the output data to what is defined in the return type.
    * This is particularly important for **security**, we'll see more of that below.

## `response_model` Parameter { #response-model-parameter }