RegularImmutableSortedSet<E> elementSet, long[] cumulativeCounts, int offset, int length) {
    this.elementSet = elementSet;
    this.cumulativeCounts = cumulativeCounts;
    this.offset = offset;
    this.length = length;
  }

  private int getCount(int index) {
    return (int) (cumulativeCounts[offset + index + 1] - cumulativeCounts[offset + index]);
  }

  @Override
  Entry<E> getEntry(int index) {

    }
    ImmutableList.Builder<E> elementsBuilder = new ImmutableList.Builder<>(entries.size());
    long[] cumulativeCounts = new long[entries.size() + 1];
    int i = 0;
    for (Entry<E> entry : entries) {
      elementsBuilder.add(entry.getElement());
      cumulativeCounts[i + 1] = cumulativeCounts[i] + entry.getCount();
      i++;
    }
    return new RegularImmutableSortedMultiset<>(