title: Zombie.js - Test if object property found
body: <p><em>Im a bit new of Zombie.js testing, and hard to search so I will ask here ...</em></p>
  
  <p><strong>Example :</strong> <em>(Globla variable)</em></p>
  
  <pre><code>hello = {"world" : "...."}
  </code></pre>
  
  <p><strong>So I test something like :</strong></p>
  
  <pre><code>describe('Check varibles', function() {
      it('If ---&gt; hello &lt;--- exits', function(done) {
          browser.assert.global('hello');
          done();
      });
  
      it('If ---&gt; hello.world &lt;--- exits', function(done) {
          // ????
          done();
      });
  });
  </code></pre>
  
  <p>I can check if <code>hello</code> is exits. <strong>But how to check</strong> if hello.world` is exits ?</p>
  
  <p><strong>I tried with :</strong></p>
  
  <pre><code>browser.assert.global('hello.world'); // AssertionError: undefined == true 
  </code></pre>