}

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~
  public void testConcat_overflow_negative() {
    int dim1 = 1 << 16;
    int dim2 = 1 << 15;
    assertThat(dim1 * dim2).isLessThan(0);
    testConcatOverflow(dim1, dim2);
  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~

        if (!sizeIfKnown.isPresent()) {
          return Optional.absent();
        }
        result += sizeIfKnown.get();
        if (result < 0) {
          // Overflow (or one or more sources that returned a negative size, but all bets are off in
          // that case)
          // Can't represent anything higher, and realistically there probably isn't anything that

   * ok if it's in a method call. If the index passed in is 0 then no copying will be done.
   */
  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) {

   * ok if it's in a method call. If the index passed in is 0 then no copying will be done.
   */
  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) {

        .webSocketUpgrade(serverListener)
        .build(),
    )
    val webSocket: WebSocket = newWebSocket()
    clientListener.assertOpen()

    // Send messages until the client's outgoing buffer overflows!
    val message: ByteString = ByteString.of(*ByteArray(1024 * 1024))
    var messageCount: Long = 0
    while (true) {
      val success = webSocket.send(message)
      if (!success) break
      messageCount++

  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~
  public void testConcat_overflow_negative() {
    int dim1 = 1 << 16;
    int dim2 = 1 << 15;
    assertThat(dim1 * dim2).isLessThan(0);
    testConcatOverflow(dim1, dim2);
  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~

  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~
  public void testConcat_overflow_negative() {
    int dim1 = 1 << 16;
    int dim2 = 1 << 15;
    assertThat(dim1 * dim2).isLessThan(0);
    testConcatOverflow(dim1, dim2);
  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~

  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~
  public void testConcat_overflow_negative() {
    int dim1 = 1 << 16;
    int dim2 = 1 << 15;
    assertThat(dim1 * dim2).isLessThan(0);
    testConcatOverflow(dim1, dim2);
  }

  @GwtIncompatible // different overflow behavior; could probably be made to work by using ~~

    int hashCode = 1;
    int n = size();
    for (int i = 0; i < n; i++) {
      hashCode = 31 * hashCode + get(i).hashCode();

      hashCode = ~~hashCode;
      // needed to deal with GWT integer overflow
    }
    return hashCode;
  }

  /*
   * Serializes ImmutableLists as their logical contents. This ensures that
   * implementation types do not leak into the serialized representation.
   */

  public static <E extends @Nullable Object> ArrayList<E> newArrayList(E... elements) {
    checkNotNull(elements); // for GWT
    // Avoid integer overflow when a large array is passed in
    int capacity = computeArrayListCapacity(elements.length);
    ArrayList<E> list = new ArrayList<>(capacity);
    Collections.addAll(list, elements);
    return list;
  }