private static int processing(AnnotationProcessorFactory factory,
                                  PrintWriter out,
                                  String... args) {
        if (out == null)
            out = new PrintWriter(System.err, true);
        com.sun.tools.apt.main.Main compiler =
            new com.sun.tools.apt.main.Main("apt", out);
        return compiler.compile(args, factory);
    }