make border radius circle for button in flutter code example

Example 1: rounded raisedbutton in flutter

RaisedButton(
                onPressed: () {},
                color: Colors.amber,
                shape: RoundedRectangleBorder(
                    borderRadius: BorderRadius.circular(10)),
                child: Text("Click This"),
              )

Example 2: A circuler border button in flutter

Padding(  padding: EdgeInsets.only(left: 150.0, right: 0.0),  child: RaisedButton(    textColor: Colors.white,    color: Colors.black,    child: Text("Search"),    onPressed: () {},    shape: new RoundedRectangleBorder(      borderRadius: new BorderRadius.circular(30.0),    ),  ),)