IndexedStack({Key key, FractionalOffset alignment: FractionalOffset.topLeft, int index: 0, List<Widget> children: const [] })

Creates a Stack widget that paints a single child.

The index argument must not be null.

Source 

IndexedStack({
  Key key,
  FractionalOffset alignment: FractionalOffset.topLeft,
  this.index: 0,
  List<Widget> children: const <Widget>[],
}) : super(key: key, alignment: alignment, children: children);