How can I distinguish internal from external updates in Firebase
<p>I'm using iOS/Swift with <a href="https://firebase.google.com" rel="nofollow">Firebase</a> as my backend.</p>

<p>When the value of a reference change, I get notified, because I'm adding an observer.</p>

<p>What I need is to be able to know when this change was triggered from my local code or from the server.</p>