code: function use(brand) {
    return function branding(file) {
      var branded = file.replace('{{brand}}', brand);
      return fs.existsSync(branded) ? branded : file.replace('{{brand}}', 'nodejitsu');
    };
  }
docs: Return a mapping function with preset brand, will default to nodejitsu files if
  the requested branded file does not exist.
  
  @param {String} brand
  @returns {Function} mapper
  @api private