title: How to remove duplicates from an unordered Immutable.List()?
body: <p>How would one remove duplicates from an unordered Immutable.List()? 
  (without using toJS() or toArray())</p>
  
  <p>e.g.</p>
  
  <pre><code>Immutable.List.of("green", "blue","green","black", "blue")
  </code></pre>