Error using usage snippet for x-ray-phantom

error.js

  .use(phantom())
       ^
TypeError: object is not a function
    at Object.<anonymous> (/Users/212341175/workspace/repos/kexp/xray.js:5:8)
    at Module._compile (module.js:460:26)
    at Object.Module._extensions..js (module.js:478:10)
    at Module.load (module.js:355:32)
    at Function.Module._load (module.js:310:12)
    at Function.Module.runMain (module.js:501:10)
    at startup (node.js:129:16)
    at node.js:814:3

xray-example.js

// usage snippet from:
// https://github.com/lapwinglabs/x-ray-phantom
xray = require('x-ray');
phantom = require('phantom');

var options = {};

xray('http://google.com')
  .use(phantom())
  .type('input', 'x-ray')
  .click('.search')
  .select([{
    $root: '.result',
    title: '.title',
    link: 'a[href]'
  }])
  .write('out.json');