// File access constants should fit in lower 16 bits (0x0000FFFF)
            assertTrue(ACE.FILE_READ_DATA <= 0x0000FFFF, "FILE_READ_DATA should fit in lower 16 bits");
            assertTrue(ACE.FILE_WRITE_DATA <= 0x0000FFFF, "FILE_WRITE_DATA should fit in lower 16 bits");
            assertTrue(ACE.FILE_WRITE_ATTRIBUTES <= 0x0000FFFF, "FILE_WRITE_ATTRIBUTES should fit in lower 16 bits");

  // array. The top bits of this value are the remaining bits of the hash value that were not used
  // in the short hash. We saw that a mask of 0x7f would keep the 7-bit value 0x6f from a full
  // hashcode of 0x89abcdef. The imaginary `hash` value would then be the remaining top 25 bits,
  // 0x89abcd80. To this is added (or'd) the `next` value, which is an index within `entries`

 * 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

   * 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.
   *
   * <p>If the argument is nonnegative, the returned result will be equal to {@code bits},
   * otherwise, the result will be equal to {@code 2^32 + bits}.
   *
   * <p>To represent unsigned decimal constants, consider {@link #valueOf(long)} instead.
   *

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();

  /**

 * 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

            int i, len, dots;
            char[] data;

            i = dots = 0; /* quick IP address validation */
            len = hostname.length();
            data = hostname.toCharArray();
            while (i < len && Character.isDigit(data[i++])) {
                if (i == len && dots == 3) {
                    // probably an IP address
                    return true;

                  + " 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

  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. */

    /**
     * Number of bytes processed so far mod. 2 power of 64.
     */
    private long count;

    /**
     * 512 bits input buffer = 16 x 32-bit words holds until reaches 512 bits.
     */
    private byte[] buffer = new byte[BLOCK_LENGTH];

    /**
     * 512 bits work buffer = 16 x 32-bit words
     */
    private final int[] X = new int[16];

    // Constructors