}

  private static class StringWrapper {
    private final String value;

    StringWrapper(String value) {
      this.value = value;
    }
  }

  @GwtIncompatible // J2CL generics problem
  public void testAndThen() {
    Converter<StringWrapper, String> first =
        new Converter<StringWrapper, String>() {
          @Override
          protected String doForward(StringWrapper object) {

    return result;
  }

  /*
   * If I understand correctly:
   *
   * This needs to be a @JsMethod so that J2CL knows to look for a JavaScript implemention of
   * it in Platform.native.js. (The JavaScript implementation inline below is visible to *GWT*, but
   * *J2CL* doesn't look at it.)
   *
   * However, once it's a @JsMethod, GWT produces a warning. That's because (a) the *other* purpose

            ArithmeticException.class,
            () -> MathPreconditions.checkInRangeForRoundingInputs(false, 1.0, RoundingMode.UP));
    // b/38490623: The string contains "1.0" under most environment but just "1" under J2CL.
    assertThat(expected).hasMessageThat().contains("1");
    assertThat(expected).hasMessageThat().contains("UP");
  }

  public void testCheckNoOverflow_success() {

public final class MoreCollectors {

  /*
   * TODO(lowasser): figure out if we can convert this to a concurrent AtomicReference-based
   * collector without breaking j2cl?
   */
  private static final Collector<Object, ?, Optional<Object>> TO_OPTIONAL =
      Collector.of(
          () -> new ToOptionalState<>(null),
          ToOptionalState::add,
          ToOptionalState::combine,

            ArithmeticException.class,
            () -> MathPreconditions.checkInRangeForRoundingInputs(false, 1.0, RoundingMode.UP));
    // b/38490623: The string contains "1.0" under most environment but just "1" under J2CL.
    assertThat(expected).hasMessageThat().contains("1");
    assertThat(expected).hasMessageThat().contains("UP");
  }

  public void testCheckNoOverflow_success() {

 * @since 21.0
 */
@GwtCompatible
public final class MoreCollectors {

  /*
   * TODO(lowasser): figure out if we can convert this to a concurrent AtomicReference-based
   * collector without breaking j2cl?
   */
  private static final Collector<Object, ?, Optional<Object>> TO_OPTIONAL =
      Collector.of(
          () -> new ToOptionalState<>(null),
          ToOptionalState::add,
          ToOptionalState::combine,

   */
  private static char[] growBuffer(char[] dest, int index, int size) {
    if (size < 0) { // overflow - should be OutOfMemoryError but GWT/j2cl don't support it
      throw new AssertionError("Cannot increase internal buffer any further");
    }
    char[] copy = new char[size];
    if (index > 0) {
      System.arraycopy(dest, 0, copy, 0, index);
    }

   *     greater than {@code b}; or zero if they are equal
   */
  @SuppressWarnings("InlineMeInliner") // Integer.compare unavailable under GWT+J2CL
  public static int compare(long a, long b) {
    return Longs.compare(flip(a), flip(b));
  }

  /**
   * Returns the least value present in {@code array}, treating values as unsigned.
   *

  }

  /**
   * {@inheritDoc}
   *
   * @since NEXT. Note, however, that Java 19+ users can call this method with any version of Guava.
   */
  @SuppressWarnings("MissingOverride") // not an override under J2CL
  @ParametricNullness
  public V resultNow() {
    Object localValue = value();
    if (localValue == null | localValue instanceof DelegatingToFuture) {
      throw new IllegalStateException("Task has not completed");

   *     greater than {@code b}; or zero if they are equal
   */
  @SuppressWarnings("InlineMeInliner") // Integer.compare unavailable under GWT+J2CL
  public static int compare(int a, int b) {
    return Ints.compare(flip(a), flip(b));
  }

  /**
   * Returns the value of the given {@code int} as a {@code long}, when treated as unsigned.
   *