title: Array of object deep comparison with lodash
body: <p>I've 2 array of objects that I'd deeply compare with <code>lodash</code></p>
  
  <p>However, I've a prob with it:</p>
  
  <pre><code>&gt; var x = [{a:1, b:2}, {c:3, d:4}];
  &gt; var y = [{b:2, a:1}, {d:4, c:3}];
  &gt; _.difference(x,y, _.isEqual);
  [ { a: 1, b: 2 }, { c: 3, d: 4 } ]
  </code></pre>
  
  <p>How should I compare to see that both are equal?</p>