title: es6 unique array of objects with set
body: <p>I came across this example for creating unique arrays with es6</p>
  
  <pre><code>[ ...new Set(array) ]
  </code></pre>
  
  <p>Which seems to work fine until I tried it with an array of objects and it didn't return unique array.</p>
  
  <p>i.e.</p>
  
  <pre><code>let item = [ ...new Set([{id:123,value:'test'},{id:123,value:'test'}]) ];
  </code></pre>
  
  <p>Why is that ?</p>