}

  @Override
  int nextIndex(int index) {
    int result = getSuccessor(index);
    return (result == ENDPOINT) ? -1 : result;
  }

  @Override
  int nextIndexAfterRemove(int oldNextIndex, int removedIndex) {
    return (oldNextIndex == size()) ? removedIndex : oldNextIndex;
  }

  private int getPredecessor(int entry) {
    return (int) (links[entry] >>> 32);
  }