title: React Navigation Drawer with type 'back' add shadow?
body: <p>When using react navigation drawer, <code>drawerType=back</code>, I feel like the because the main content is at the 'front', it should cast a shadow on the drawer when it's out, but there is no option to do this, and I can't figure out a way to do so. Elevation is useless for applying anything customisable, the <code>react-native-shadow-2</code> package acts bizarrely and unpredictably.</p>
  <p>Here's what I have:
  <a href="https://i.stack.imgur.com/zKuaI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zKuaI.jpg" alt="enter image description here" /></a></p>
  <p>and what I want:</p>
  <p><a href="https://i.stack.imgur.com/gviTN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gviTN.png" alt="enter image description here" /></a></p>
  <p>Is there any way to achieve this?</p>