title: Zombiejs document function callback
body: <p>I'm trying to call a method on an object in window which can have a callback, like this:</p>
  
  <pre><code>it('should be logged in into Facebook', function(done){
    browser.visit('/test').then(function(){
      browser.window.FB.getLoginStatus(function(response) {
        if (response.status === 'connected') done();
      });
    });
  });
  </code></pre>
  
  <p>But the callback is never executed, although I can see the requests in resources. Furthermore, I tried with eval and it does not work either:</p>
  
  <pre><code>it('should be logged in into Facebook', function(done){
    browser.visit('/test').then(function(){
      browser.evaluate( 'FB.getLoginStatus(function(response) { console.log("connected") // does not print; })' );
    });
  });
  </code></pre>
  
  <p>What can be the problem? </p>