*   absent.
   */

  /**
   * If {@code key} is not already associated with a value or if {@code key} is associated with
   * zero, associate it with {@code newValue}. Returns the previous value associated with {@code
   * key}, or zero if there was no mapping for {@code key}.
   */
  long putIfAbsent(K key, long newValue) {
    while (true) {

  void clear();

  /**
   * Associates the specified value with the specified keys. If the table already contained a
   * mapping for those keys, the old value is replaced with the specified value.
   *
   * @param rowKey row key that the value should be associated with
   * @param columnKey column key that the value should be associated with
   * @param value value to be associated with the specified keys

        return Optional.ofNullable(location);
    }

    /**
     * Returns the path type associated to the given {@code javax.tool} location.
     * This method is the converse of {@link #location()}.
     *
     * @param location identification of a path in the {@code javax.tool} API
     * @return Java path type associated to the given location
     */

  void clear();

  /**
   * Associates the specified value with the specified keys. If the table already contained a
   * mapping for those keys, the old value is replaced with the specified value.
   *
   * @param rowKey row key that the value should be associated with
   * @param columnKey column key that the value should be associated with
   * @param value value to be associated with the specified keys

   *     associated with the key. The collection <i>may</i> be modifiable, but updating it will have
   *     no effect on the multimap.
   */
  @CanIgnoreReturnValue
  Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**
   * Removes all values associated with the key {@code key}.
   *

- MinIO optionally queries the AD/LDAP server for a list of groups that the user is a member of.
- MinIO then checks if there are any policies [explicitly associated](#managing-usergroup-access-policy) with the user or their groups.

        if (totalHits != null) {
            return totalHits.value();
        }
        return 0;
    }

    /**
     * Deletes all documents associated with the specified session ID.
     *
     * @param sessionId the session ID to delete documents for
     * @return the number of documents that were deleted
     */

        hmac.digest(response, 0, 16);
        System.arraycopy(clientChallenge, 0, response, 16, 8);
        return response;
    }

    /**
     * Generate the Unicode MD4 hash for the password associated with these credentials.
     *
     * @param password the password to hash
     * @param challenge the server challenge bytes
     * @return the calculated response

     *   <li>If this field's value == null because it originally belonged to another thread and that
     *       thread cleared it, we still know that it's not associated with our thread
     *   <li>If this field's value == null because it was associated with our thread and was
     *       cleared, we know that we're not executing inline any more
     * </ul>
     *

   *     associated with the key. The collection <i>may</i> be modifiable, but updating it will have
   *     no effect on the multimap.
   */
  @CanIgnoreReturnValue
  Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**
   * Removes all values associated with the key {@code key}.
   *