}

    /*
     * We need the top SIGNIFICAND_BITS + 1 bits, including the "implicit" one bit. To make rounding
     * easier, we pick out the top SIGNIFICAND_BITS + 2 bits, so we have one to help us round up or
     * down. twiceSignifFloor will contain the top SIGNIFICAND_BITS + 2 bits, and signifFloor the
     * top SIGNIFICAND_BITS + 1.
     *

    // 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
   * interpreted as an unsigned 32-bit value. Specifically, the sign bit of {@code bits} is
   * interpreted as a normal bit, and all other bits are treated as usual.
   *

  private final Key key;

  private final String toString;
  private final int bits;
  private final boolean supportsClone;

  MacHashFunction(String algorithmName, Key key, String toString) {
    this.prototype = getMac(algorithmName, key);
    this.key = checkNotNull(key);
    this.toString = checkNotNull(toString);
    this.bits = prototype.getMacLength() * Byte.SIZE;
    this.supportsClone = supportsClone(prototype);
  }

  }

  private static final int ENDPOINT = -2;

  /**
   * Contains the link pointers corresponding with the entries, in the range of [0, size()). The
   * high 32 bits of each long is the "prev" pointer, whereas the low 32 bits is the "succ" pointer
   * (pointing to the next entry in the linked list). The pointers in [size(), entries.length) are
   * all "null" (UNSET).
   *

    try {
      Object unused = digest.clone();
      return true;
    } catch (CloneNotSupportedException e) {
      return false;
    }
  }

  @Override
  public int bits() {
    return bytes * Byte.SIZE;
  }

  @Override
  public String toString() {
    return toString;
  }

  private static MessageDigest getMessageDigest(String algorithmName) {
    try {

    assertThrows(IllegalArgumentException.class, () -> DoubleUtils.ensureNonNegative(Double.NaN));
  }

  public void testOneBits() {
    assertEquals(DoubleUtils.ONE_BITS, Double.doubleToRawLongBits(1.0));
  }

  private static void failFormat(String template, Object... args) {
    fail(String.format(template, args));
  }

  private final int bits;
  private final String toString;

  ChecksumHashFunction(
      ImmutableSupplier<? extends Checksum> checksumSupplier, int bits, String toString) {
    this.checksumSupplier = checkNotNull(checksumSupplier);
    checkArgument(bits == 32 || bits == 64, "bits (%s) must be either 32 or 64", bits);
    this.bits = bits;
    this.toString = checkNotNull(toString);
  }

    for (int b = 0; b < 4; ++b) {
      for (int bit = 128; bit != 0; bit >>= 1) {
        expected[b][bit] = next;
        next = advanceOneBit(next);
      }
    }
    for (int b = 0; b < 4; ++b) {
      expected[b][0] = 0;
      for (int bit = 2; bit < 256; bit <<= 1) {
        for (int i = bit + 1; i < (bit << 1); i++) {
          expected[b][i] = expected[b][bit] ^ expected[b][i ^ bit];
        }
      }
    }

   * interpreted as an unsigned 64-bit value. Specifically, the sign bit of {@code bits} is
   * interpreted as a normal bit, and all other bits are treated as usual.
   *
   * <p>If the argument is nonnegative, the returned result will be equal to {@code bits},
   * otherwise, the result will be equal to {@code 2^64 + bits}.
   *

        // Three-byte form.
        if (index + 1 >= end) {
          return false;
        }
        int byte2 = bytes[index++];
        if (byte2 > (byte) 0xBF
            // Overlong? 5 most significant bits must not all be zero.
            || (byte1 == (byte) 0xE0 && byte2 < (byte) 0xA0)
            // Check for illegal surrogate codepoints.
            || (byte1 == (byte) 0xED && (byte) 0xA0 <= byte2)