@Override
  public HashCode hashBytes(byte[] input, int off, int len) {
    checkPositionIndexes(off, off + len, input.length);
    return HashCode.fromLong(fingerprint(input, off, len));
  }

  @Override
  public int bits() {
    return 64;
  }

  @Override
  public String toString() {
    return "Hashing.fingerprint2011()";
  }

  // End of public functions.

  @VisibleForTesting

    @Override
    public HashCode hashBytes(byte[] input, int off, int len) {
      return HashCode.fromBytes(Arrays.copyOfRange(input, off, off + len));
    }

    @Override
    public int bits() {
      throw new UnsupportedOperationException();
    }
  }

   * tables, that otherwise encounter collisions for hash codes that do not differ in lower or upper
   * bits.
   *
   * @param h hash code
   */
  static int rehash(int h) {
    // Spread bits to regularize both segment and index locations,
    // using variant of single-word Wang/Jenkins hash.
    // TODO(kevinb): use Hashing/move this to Hashing?

        LockFreeBitArray bits) {
      long bitSize = bits.bitSize();
      long hash64 = Hashing.murmur3_128().hashObject(object, funnel).asLong();
      int hash1 = (int) hash64;
      int hash2 = (int) (hash64 >>> 32);

      boolean bitsChanged = false;
      for (int i = 1; i <= numHashFunctions; i++) {
        int combinedHash = hash1 + (i * hash2);
        // Flip all the bits if it's negative (guaranteed positive number)

    /**
     * Sets {@code numHashFunctions} bits of the given bit array, by hashing a user element.
     *
     * <p>Returns whether any bits changed as a result of this operation.
     */
    <T extends @Nullable Object> boolean put(
        @ParametricNullness T object,
        Funnel<? super T> funnel,
        int numHashFunctions,
        LockFreeBitArray bits);

    /**

    long numeratorAccum = n;
    long denominatorAccum = 1;

    int bits = LongMath.log2(n, CEILING);

    int numeratorBits = bits;

    for (int i = 1; i < k; i++) {
      int p = n - i;
      int q = i + 1;

      // log2(p) >= bits - 1, because p >= n/2

      if (numeratorBits + bits >= Long.SIZE - 1) {
        // The numerator is as big as it can get without risking overflow.

                  + " output bits; The unaffected bits are "
                  + "as follows: "
                  + ~(same & diff)
                  + ". This was "
                  + "determined after "
                  + count
                  + " trials.");
        }
      }
    }
  }

  /**
   * Test for avalanche. Avalanche means that output bits differ with roughly 1/2 probability on

   * metadata} is the size that the arrays should be allocated with. Once the arrays have been
   * allocated, the value of {@code metadata} combines the number of bits in the "short hash", in
   * its bottom {@value CompactHashing#HASH_TABLE_BITS_MAX_BITS} bits, with a modification count in
   * the remaining bits that is used to detect concurrent modification during iteration.
   */
  private transient int metadata;

  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);
  }

   * 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}.
   *
   * <p>To represent decimal constants less than {@code 2^63}, consider {@link #valueOf(long)}