code: function processArgv(app, argv, options) {
    var opts = utils.extend({}, options);
    if (opts.expand === false || argv.expand === 'false') {
      return argv;
    }
  
    argv = utils.expandArgs(argv, opts);
    return sortArgs(app, argv, opts);
  }
docs: Expand command line arguments into the format we need to pass
  to `app.cli.process()`.
  
  @param {Object} `app` Application instance
  @param {Object} `argv` argv object, parsed by minimist
  @param {Array} `options.first` The keys to pass to `app.cli.process()` first.
  @param {Array} `options.last` The keys to pass to `app.cli.process()` last.
  @param {Array} `options.keys` Flags to whitelist
  @return {Object} Returns the `argv` object with sorted keys.