*/

  private int getPredecessor(int entry) {
    return ((int) (link(entry) >>> 32)) - 1;
  }

  @Override
  int getSuccessor(int entry) {
    return ((int) link(entry)) - 1;
  }

  private void setSuccessor(int entry, int succ) {
    long succMask = (~0L) >>> 32;
    setLink(entry, (link(entry) & ~succMask) | ((succ + 1) & succMask));
  }

   */

  private int getPredecessor(int entry) {
    return requirePredecessors()[entry] - 1;
  }

  @Override
  int getSuccessor(int entry) {
    return requireSuccessors()[entry] - 1;
  }

  private void setSuccessor(int entry, int succ) {
    requireSuccessors()[entry] = succ + 1;
  }

  private void setPredecessor(int entry, int pred) {