title: Firebase Multiple Accounts are signed at the same time
body: <p>I want my users to sign in with multiple accounts (Not linking multiple providers)</p>
  
  <p>like gmail, it allows you to use multiple signed in accounts at the same time
  you can check all inboxes for all accounts at the same time</p>
  
  <p>e.g. I am a User and I want to use two accounts
  john@example.com &amp; john21@example.com</p>
  
  <p>I want both emails signed in (there are two auth tokens in this case)</p>
  
  <p>I have searched about it in Firebase docs, I couldn't find anything</p>
  
  <p>Is this possible in Firebase Auth?</p>