code: function NativeFlow(options) {
    this.app = options.app;
    this.instructions = options.instructions || defaultInstructions;
    this.prompt = options.prompt || defaultPrompt;
    this.redirectUri = oauthUtil.NATIVE_REDIRECT_URI;
  }
docs: An Oauth flow that can be run from the console or an app that does
  not have the ability to open and manage a browser on its own.
  @param {Object} options
  @option {App} app App to authenticate for
  @option {String function(String)} [instructions] Function returning the
  instructions to output to the user. Passed the authorize url.
  @option {String function()} [prompt] String to output immediately before
  waiting for a line from stdin.
  @constructor