title: Flutter: CupertinoTabBar does not disappear when moving to the next screen
body: <p>I'm running the Flutter Gallery example from Google: </p>
  
  <p><a href="https://github.com/flutter/flutter/blob/master/examples/flutter_gallery/lib/demo/cupertino/cupertino_navigation_demo.dart" rel="noreferrer">https://github.com/flutter/flutter/blob/master/examples/flutter_gallery/lib/demo/cupertino/cupertino_navigation_demo.dart</a></p>
  
  <p>In the gif below, notice how when I navigate from one screen to the next, the Cupertino Tab Bar stays at the bottom of the screen.
  The reason why this is the case is that it is a widget that lays within the parent widget CupertinoNavigationDemo and while the tabs are swapped in and out of the view, the tab bar remains.</p>
  
  <p>Is there a way to get rid of the Tab Bar when navigating?</p>
  
  <p><a href="https://i.stack.imgur.com/U4FFj.gif" rel="noreferrer"><img src="https://i.stack.imgur.com/U4FFj.gif" alt="enter image description here"></a></p>