code: function (flagKey) {
    var flags = _.isUndefined(flagKey) ? FLAGS.general : FLAGS[flagKey];
  
    return !flags ? "" : _.map(flags, function (val, key) {
      return chalk.cyan("--" + key) + ": " + val.desc;
    }).join("\n\n  ");
  }
docs: Retrieve help.
  
  @param   {String} flagKey  Key of flags to return or `undefined` for general
  @returns {String}          Help string