code: public List<Feature> getSortedFeatures() {
          ArrayList<Feature> result = new ArrayList<>(pcm.getConcreteFeatures());
          Collections.sort(result, new Comparator<Feature>() {
              @Override
              public int compare(Feature f1, Feature f2) {
                  Integer fp1 = getFeaturePosition(f1);
                  Integer fp2 = getFeaturePosition(f2);
                  return fp1.compareTo(fp2);
              }
          });
          return result;
      }
docs: Return the sorted features concordingly with metadata
  @return an ordered list of features