Firebase append data to node
<p>How can I append data to a node in Firebase? The value update would just be a string, not a dictionary.</p>

<p>Firebase should be able to increment each items. I thought <code>update</code> would work, but that only updates a dictionary. When I attempt to set the value, it erases everything.</p>

<pre><code>FIRDatabase().reference().database.childRef(refUrl: path).updateChildValues([:])
</code></pre>

<p>Example:</p>

<pre><code>node{
      1:itemOne
      2:itemTwo
      3:itemThree
}
</code></pre>