svoid ai_parseTree_makeTotalWeights(Element e, double weight) {
  e.totalWeight = weight*e.weight;
  
  for (Element child : unnull(e.children))
    ai_parseTree_makeTotalWeights(child, e.totalWeight);
    
  sortInPlaceByCalculatedFieldDesc(e.children, func(Element e) -> Double { e.totalWeight });
}