code: public static void main(String[] args) {
          if (args.length < 1) {
              System.out.println("Usage: PortableTypeGenerator <classDir>");
              System.exit(0);
          }
  
          try {
              instrumentClasses(new File(args[0]));
          }
          catch (Exception e) {
              System.out.println("ERROR:" + e.getMessage());
          }
      }
docs: ---- command line utility implementation -----------------------------------------------------------------------