title: How do I add equal elements to an array in Firestore in Flutter?
body: <p>I just figured out that in Flutter</p>
  
  <pre><code>List&lt;int&gt; values = [1,2,3,1,2,3];
  Firestore.instance.path.updateData({"values": FieldValue.arrayUnion(values)});
  </code></pre>
  
  <p>results in the Firestore Array</p>
  
  <pre><code>(Firestore Array) [1,2,3]
  </code></pre>
  
  <p>Obviously the values are somehow mapped, removing duplicate values, although I can manually add duplicate values online in the Firebase panel (the datatype is called array respectively).</p>
  
  <p>Is there a way to bypass this behaviour or is this a bug?</p>