android studio - Refraction Error and i am unable to extract Method error message

Question

The selection does not cover a set of statements or an expression. Extend selection to a valid range.

Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text('Time Tracker'),
          elevation: 3.0),
      body: Container(
        color: Colors.yellow,
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            Container(
              color: Colors.orange,
              child: SizedBox(
                width: 100.0,
                height: 100.0,
              ),
            ),
        Container(
        color: Colors.red,
        child: SizedBox(
          width: 100.0,
          height: 100.0,
        ),
        ),
            Container(
              color: Colors.purple,
              child: SizedBox(
                width: 100.0,
                height: 100.0,
              ),
            ),
          ],
        ),
      ),
    );
}

Answer 1

等待大神答复