code: function optimizeJs(source) {
      var ret = '';
      ret = parser.parse(source);
      ret = uglify.ast_mangle(ret, opts.uglifyJs.mangle);
      ret = uglify.ast_lift_variables(ret);
      ret = uglify.ast_squeeze(ret);
      ret = uglify.gen_code(ret, opts.uglifyJs.code);
      return ret;
    }
docs: /*
  do uglify