Need a Window on IOS but a View on Android in Alloy?

index.xml

<Alloy>
  <Window module="xp.ui">
    <Label>Hello World</Label>
  </Window>
</Alloy>

xp.ui.js

exports.createWindow = function(args) {
  return Ti.UI[OS_IOS ? 'createWindow' : 'createView'](args);
};