code: function wrap(body, extKeys) {
      const wrapper = [
          '(function (exports, require, module, __filename, __dirname',
          ') { ',
          '\n});'
      ];
  
      extKeys = extKeys ? `, ${extKeys}` : '';
  
      return wrapper[0] + extKeys + wrapper[1] + body + wrapper[2];
  }
docs: Wrap code with function expression
  Use nodejs style default wrapper
  
  @param {String} body
  @param {String[]} [extKeys] keys to extend function args
  @returns {String}