title: Is It Possible To Get The ID Before It Was Added?
body: <p>I know that in <code>Realtime Database</code> I could get the <code>push ID</code> before it was added like this:</p>
  
  <pre><code> DatabaseReference databaseReference= FirebaseDatabase.getInstance().getReference();
   String challengeId=databaseReference.push().getKey();
  </code></pre>
  
  <p>and then I could add it using this ID. </p>
  
  <p>Can I get it also in the <code>Cloud Firestore?</code></p>