docs: public TreeMap<Bits, Long> computeSums() {
      final TreeMap<Bits, Long> sums = new TreeMap<Bits, Long>();
      long total = 0;
      for (final Entry<Bits, AtomicInteger> e : this.map.entrySet()) {
        sums.put(e.getKey(), total += e.getValue().get());
      }
      return sums;
    }