private void render(InputStream is, TokenRenderer renderer, PrintStream out) throws Exception {
ANTLRInputStream input = new ANTLRInputStream(is);
JavaLexer lexer = new JavaLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
DebugEventListener builder = new ParseTokenListener(renderer, out);
JavaParser parser = new JavaParser(tokens, builder);
// launch the parser starting at compilation unit
parser.compilationUnit();
}