title: Flutter Back button with return data
body: <p>I have an interface with two buttons that pop and return true or false, like so:</p>
  
  <pre><code>onPressed: () =&gt; Navigator.pop(context, false)
  </code></pre>
  
  <p>I need to adapt the back button in the appbar, so it pops and also returns false. Is there a way to accomplish this?</p>