/**
     * Returns the input stream for the Maven execution, if running in embedded mode.
     *
     * @return an {@link Optional} containing the input stream, or empty if not applicable
     */
    @Nonnull
    default Optional<InputStream> stdIn() {
        return Optional.ofNullable(parserRequest().stdIn());
    }

    /**
     * Returns the output stream for the Maven execution, if running in embedded mode.

  }

  /**
   * Returns an immutable array containing all the values from {@code stream}, in order.
   *
   * @since 22.0 (but only since 33.4.0 in the Android flavor)
   */
  public static ImmutableIntArray copyOf(IntStream stream) {
    // Note this uses very different growth behavior from copyOf(Iterable) and the builder.
    int[] array = stream.toArray();
    return (array.length == 0) ? EMPTY : new ImmutableIntArray(array);
  }

- ✅ Failed extraction includes descriptive error messages
- ✅ Null input stream validation
- ✅ Error messages include file type context

---

### 2. FilenameExtractorEnhancedTest.java
**Purpose**: Test FilenameExtractor edge cases and new documentation.

**Key Test Areas**:
- Parameter handling (null, empty, missing)
- Special character handling
- Input stream validation (not consumption)
- Edge cases (long filenames, paths, whitespace)

   */
  @GwtIncompatible // java.io.ObjectOutputStream
  private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(keyTypeOrObjectUnderJ2cl);
    stream.writeObject(valueTypeOrObjectUnderJ2cl);
    Serialization.writeMap(this, stream);
  }

  @SuppressWarnings("unchecked") // reading fields populated by writeObject

        if (StringUtil.isBlank(slackWebhookUrls)) {
            return;
        }
        final String body = toSlackMessage(discloser);
        StreamUtil.split(slackWebhookUrls, "[,\\s]").of(stream -> stream.filter(StringUtil::isNotBlank).forEach(url -> {
            try (CurlResponse response = Curl.post(url).header("Content-Type", "application/json").body(body).execute()) {
                if (response.getHttpStatusCode() == 200) {

        });

        userBhv.selectCursor(cb -> cb.query().setGroups_Equal(group.getId()), entity -> {
            entity.setGroups(
                    stream(entity.getGroups()).get(stream -> stream.filter(s -> !s.equals(group.getId())).toArray(n -> new String[n])));
            userBhv.insertOrUpdate(entity);
        });

    }

    /**

            }
        }
        form.fields.entrySet().stream().filter(e -> e.getValue() != null).forEach(e -> {
            final String key = LaFunctions.u(e.getKey());
            stream(e.getValue()).of(stream -> stream.filter(StringUtil::isNotBlank)
                    .forEach(s -> pagingQueryList.add("fields." + key + "=" + LaFunctions.u(s))));
        });
        form.as.entrySet().stream().filter(e -> e.getValue() != null).forEach(e -> {

                }
                stream(accessToken.getPermissions()).of(stream -> stream.forEach(permissionSet::add));
                final String name = accessToken.getParameterName();
                stream(request.getParameterValues(name)).of(stream -> stream.filter(StringUtil::isNotBlank).forEach(permissionSet::add));
                return OptionalEntity.of(permissionSet);

      is CloseStream -> {
        if (stream != null) {
          stream.close(ErrorCode.fromHttp2(effect.http2ErrorCode)!!, null)
        } else {
          socket.close()
        }
      }

      ShutdownConnection -> {
        if (stream != null) {
          stream.connection.shutdown(ErrorCode.NO_ERROR)
        } else {
          socket.close()
        }
      }

      is CloseSocket -> {

     */
    protected WriterUtil() {
    }

    /**
     * Creates a {@link Writer} to output to a stream with the specified encoding.
     *
     * @param os the stream (must not be {@literal null})
     * @param encoding the encoding (must not be {@literal null} or empty)
     * @return a {@link Writer} to output to the stream
     */
    public static Writer create(final OutputStream os, final String encoding) {