How to use Expanded in SingleChildScrollView?

 SingleChildScrollView(

    child: ConstrainedBox(
        constraints: BoxConstraints(minWidth: MediaQuery.of(context).size.width),
        child: Column(
            //mainAxisAlignment: MainAxisAlignment.center,
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: <Widget>[
                Expanded(
                    child: Text('Hello World!'),
                ),
            ],
        ),
    )
)