title: How to use same key for multiple widget in flutter?
body: <p>I have a backdrop widget with a key, the backdrop widget has a gesture when drag down it will close, the problem when i open it in another widget, it cannot closed and trhowing error <code>Duplicate GlobalKey detected in widget tree.</code></p>
  
  <p>i call key from all page that use the backdrop with this</p>
  
  <pre><code>final backdropKey = GlobalKey(debugLabel: 'Backdrop');
  </code></pre>
  
  <p>how to fix this problem?</p>