docs: private static ClassicCounter<Integer> getWeights(List<Pair<Double, ClassicCounter<Integer>>> supportVectors) {
      ClassicCounter<Integer> weights = new ClassicCounter<Integer>();
      for (Pair<Double, ClassicCounter<Integer>> sv : supportVectors) {
        ClassicCounter<Integer> c = new ClassicCounter<Integer>(sv.second());
        Counters.multiplyInPlace(c, sv.first());
        Counters.addInPlace(weights, c);
      }
      return weights;
    }