}

  @Override
  @CheckForNull
  public E ceiling(E element) {
    int index = tailIndex(element, true);
    return (index == size()) ? null : elements.get(index);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    int index = tailIndex(element, false);
    return (index == size()) ? null : elements.get(index);
  }

  @Override

  }

  @Override
  public ImmutableSortedMultiset<E> tailMultiset(E lowerBound, BoundType boundType) {
    return getSubMultiset(
        elementSet.tailIndex(lowerBound, checkNotNull(boundType) == CLOSED), length);
  }

  ImmutableSortedMultiset<E> getSubMultiset(int from, int to) {
    checkPositionIndexes(from, to, length);
    if (from == to) {