how to courve the edges of the container in flutter code example

Example 1: container flutter border radius

Container(
	decoration: BoxDecoration(
    	color: Colors.blue,
    	borderRadius: BorderRadius.all(
    		Radius.circular(10)
    	)
    )
)

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"),
           )
         ),
        ),