private static final ImmutableSet<Integer> TEST_INTS;
  private static final ImmutableSet<Long> TEST_LONGS;

  private static int force32(int value) {
    // GWT doesn't consistently overflow values to make them 32-bit, so we need to force it.
    return value & 0xffffffff;
  }

  static {
    ImmutableSet.Builder<Integer> testIntsBuilder = ImmutableSet.builder();

   * thrown by {@linkplain MoreExecutors#directExecutor direct execution}) will be caught and
   * logged.
   *
   * <p>Note: If your listener is lightweight -- and will not cause stack overflow by completing
   * more futures or adding more {@code directExecutor()} listeners inline -- consider {@link
   * MoreExecutors#directExecutor}. Otherwise, avoid it: See the warnings on the docs for {@code
   * directExecutor}.

   * thrown by {@linkplain MoreExecutors#directExecutor direct execution}) will be caught and
   * logged.
   *
   * <p>Note: If your listener is lightweight -- and will not cause stack overflow by completing
   * more futures or adding more {@code directExecutor()} listeners inline -- consider {@link
   * MoreExecutors#directExecutor}. Otherwise, avoid it: See the warnings on the docs for {@code
   * directExecutor}.

    }
    return result.readUtf8()
  }

  /** Used for tags and subidentifiers. */
  private fun readVariableLengthLong(): Long {
    // TODO(jwilson): detect overflow.
    var result = 0L
    while (true) {
      val byteN = source.readByte().toLong() and 0xff
      if ((byteN and 0b1000_0000L) == 0b1000_0000L) {
        result = (result + (byteN and 0b0111_1111)) shl 7

  public static final UnsignedInteger MAX_VALUE = fromIntBits(-1);

  private final int value;

  private UnsignedInteger(int value) {
    // GWT doesn't consistently overflow values to make them 32-bit, so we need to force it.
    this.value = value & 0xffffffff;
  }

  /**
   * Returns an {@code UnsignedInteger} corresponding to a given bit representation. The argument is

  }

  @J2ktIncompatible
  @GwtIncompatible // threads
  public void testOverflowTimeout() throws Exception {
    // First, sanity check that naive multiplication would really overflow to a negative number:
    long nanosPerSecond = NANOSECONDS.convert(1, SECONDS);
    assertThat(nanosPerSecond * Long.MAX_VALUE).isLessThan(0L);

    accumulator.add(ONE_VALUE, OTHER_ONE_VALUE);
    for (int power = 1; power < Long.SIZE - 1; power++) {
      accumulator.addAll(accumulator.snapshot());
    }
    // Should overflow without throwing.
    accumulator.addAll(accumulator.snapshot());
    assertThat(accumulator.count()).isLessThan(0L);
  }

  public void testXStats() {

  }

  @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 ~~