add border radius to container only on the top corners flutter code example

Example 1: flutter container border radius only left

borderRadius: BorderRadius.only(
          topRight: Radius.circular(10.0),
          bottomRight: Radius.circular(10.0)),

Example 2: flutter rounded container transperent corners

new Container(
          height: 300.0,
          color: Colors.transparent,
          child: new Container(
            decoration: new BoxDecoration(
              color: Colors.green,
              borderRadius: new BorderRadius.only(
                topLeft: const Radius.circular(40.0),
                topRight: const Radius.circular(40.0),
              )
            ),
            child: new Center(
            child: new Text("Hi modal sheet"),
           )
         ),
        ),