code: public static void main(String[] args) {
      ClassCache cache = new ClassCache();
      Iterator<String> packages = cache.packages();
      List<String> sorted = new ArrayList<>();
      while (packages.hasNext())
        sorted.add(packages.next());
      Collections.sort(sorted);
      for (String key: sorted)
        System.out.println(key + ": " + cache.getClassnames(key).size());
    }
docs: For testing only.
  
  @param args	ignored