List<Optional<Object>> optionals = ImmutableList.of(Optional.absent(), Optional.absent());
    assertThat(Optional.presentInstances(optionals)).isEmpty();
  }

  public void testPresentInstances_somePresent() {
    List<Optional<String>> optionals =
        ImmutableList.of(Optional.of("a"), Optional.<String>absent(), Optional.of("c"));

   *
   * @since 11.0 (generics widened in 13.0)
   */
  public static <T> Iterable<T> presentInstances(
      Iterable<? extends Optional<? extends T>> optionals) {
    checkNotNull(optionals);
    return () ->
        new AbstractIterator<T>() {
          private final Iterator<? extends Optional<? extends T>> iterator =
              checkNotNull(optionals.iterator());

  }

  private static final Function<Object, Optional<?>> NULLABLE_TO_OPTIONAL =
      new Function<Object, Optional<?>>() {
        @Override
        public Optional<?> apply(@Nullable Object obj) {
          return Optional.fromNullable(obj);
        }
      };

  private static final Function<Optional<?>, @Nullable Object> OPTIONAL_TO_NULLABLE =
      new Function<Optional<?>, @Nullable Object>() {
        @Override

   * Predicates.notNull())}, static importing as necessary.
   *
   * <p><b>Note:</b> if {@code first} is represented as an {@link Optional}, this can be
   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *
   * <p><b>Java 9 users:</b> use {@code java.util.Objects.requireNonNullElse(first, second)}

   * Predicates.notNull())}, static importing as necessary.
   *
   * <p><b>Note:</b> if {@code first} is represented as an {@link Optional}, this can be
   * accomplished with {@link Optional#or(Object) first.or(second)}. That approach also allows for
   * lazy evaluation of the fallback instance, using {@link Optional#or(Supplier)
   * first.or(supplier)}.
   *
   * <p><b>Java 9 users:</b> use {@code java.util.Objects.requireNonNullElse(first, second)}

            .add("field11", Arrays.asList("Hello"))
            .add("field12", new ArrayList<>())
            .add("field13", new HashMap<>())
            // Optionals
            .add("field26", Optional.of("World"))
            .add("field27", Optional.absent())
            // Arrays
            .add("field31", new Object[] {"!!!"})
            .add("field32", new boolean[0])
            .add("field33", new byte[0])

- Added support for CEL expressions with escaped names in the structured authentication config. Using `[...]` to access claims or user data was recommended when names contained characters that would otherwise need escaping. CEL optionals with `?` could be used where has was not applicable — for example, `claims[?"kubernetes.io"]` or `user.extra[?"domain.io/foo"]`. ([#131574](https://github.com/kubernetes/kubernetes/pull/131574), [@enj](https://github.com/enj)) [SIG API Machinery...

    "com.oracle.svm.core.annotate;resolution:=optional," +
    "com.oracle.svm.core.configure;resolution:=optional," +
    "dalvik.system;resolution:=optional," +
    "org.conscrypt;resolution:=optional," +
    "org.bouncycastle.*;resolution:=optional," +
    "org.openjsse.*;resolution:=optional," +
    "org.graalvm.nativeimage;resolution:=optional," +
    "org.graalvm.nativeimage.hosted;resolution:=optional," +

    ) : Closeable by body

    internal companion object {
      /** These options follow the boundary. */
      val afterBoundaryOptions =
        Options.of(
          // 0.  "\r\n"  More parts.
          "\r\n".encodeUtf8(),
          // 1.  "--"    No more parts.
          "--".encodeUtf8(),
          // 2.  " "     Optional whitespace. Only used if there are more parts.
          " ".encodeUtf8(),

- Introduce support for CEL optionals (see [CEL spec proposal 246](https://github.com/google/cel-spec/wiki/proposal-246)).
  This feature will not be fully enabled until a future Kubernetes release (likely to be v1.29), but is added in v1.28 to enable