svoid findLowestEntrySizeForHyperCompactTreeSet() {
  new LowestDouble lowest;
  
  repeat 100 {
    int digits = random(1, 6);
    int m = random(1, pow10_int(digits)), n = random(m);
    var set = addAndRemoveSomeRandomStrings(new HyperCompactTreeSet, m, n);
    Cl<HyperCompactTreeSet.NonLeaf> l = set.unoptimizedNodes();
    if (nempty(l))
      print("Unoptimized nodes: " + mapToMultiSet(l, node ->  className(node) + ": " + className(node.left) + ", " + className(node.right));
    print("m=" + m + ", n=" + n + ". " + renderCollectionBytesPerEntry(set));
    lowest.put(collectionBytesPerEntry(set));
  }
  print(lowest);
}