static final byte UNSET = 0;

  /** Number of bits used to store the numbers of hash table bits (max 30). */
  private static final int HASH_TABLE_BITS_MAX_BITS = 5;

  /** Use high bits of metadata for modification count. */
  static final int MODIFICATION_COUNT_INCREMENT = (1 << HASH_TABLE_BITS_MAX_BITS);

  /** Bitmask that selects the low bits of metadata to get hashTableBits. */

  static final byte UNSET = 0;

  /** Number of bits used to store the numbers of hash table bits (max 30). */
  private static final int HASH_TABLE_BITS_MAX_BITS = 5;

  /** Use high bits of metadata for modification count. */
  static final int MODIFICATION_COUNT_INCREMENT = (1 << HASH_TABLE_BITS_MAX_BITS);

  /** Bitmask that selects the low bits of metadata to get hashTableBits. */

public abstract class HashCode {
  HashCode() {}

  /** Returns the number of bits in this hash code; a positive multiple of 8. */
  public abstract int bits();

  /**
   * Returns the first four bytes of {@linkplain #asBytes() this hashcode's bytes}, converted to an
   * {@code int} value in little-endian order.
   *
   * @throws IllegalStateException if {@code bits() < 32}
   */
  public abstract int asInt();

  /**

    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

    // the output, so the input must be at least 32 bits, since the output has to be that long
    assertPutString(new char[] {'p', HashTestUtils.randomLowSurrogate(new Random())});
  }

  public void testPutStringWithHighSurrogate() {
    // we pad because the dummy hash function we use to test this, merely copies the input into
    // the output, so the input must be at least 32 bits, since the output has to be that long

    // the output, so the input must be at least 32 bits, since the output has to be that long
    assertPutString(new char[] {'p', HashTestUtils.randomLowSurrogate(new Random())});
  }

  public void testPutStringWithHighSurrogate() {
    // we pad because the dummy hash function we use to test this, merely copies the input into
    // the output, so the input must be at least 32 bits, since the output has to be that long

 * the operation and the desired access bits are compared to the SID
 * and access mask of each ACE. If the SID matches, the allow/deny flags
 * and access mask are considered. If the ACE is a "deny"
 * ACE and <i>any</i> of the desired access bits match bits in the access
 * mask of the ACE, the whole access check fails. If the ACE is an "allow"
 * ACE and <i>all</i> of the bits in the desired access bits match bits in

pkg log, method (*Logger) Writer() io.Writer
pkg math/bits, func Add(uint, uint, uint) (uint, uint)
pkg math/bits, func Add32(uint32, uint32, uint32) (uint32, uint32)
pkg math/bits, func Add64(uint64, uint64, uint64) (uint64, uint64)
pkg math/bits, func Div(uint, uint, uint) (uint, uint)
pkg math/bits, func Div32(uint32, uint32, uint32) (uint32, uint32)
pkg math/bits, func Div64(uint64, uint64, uint64) (uint64, uint64)

   * 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;