title: showModalBottomSheet and Border Radius
body: <p>I want to make a showModalBottomSheet with a container in Flutter. I want this container to have rounded the top borders but, when I tried this, there are a few small uncolored spaces in the corners. How can I delete them?</p>
  <p>This is the code I used:</p>
  <pre><code>class OverlayWidget extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return ElevatedButton(
        child: const Text('showModalBottomSheet'),
        onPressed: () {
          showModalBottomSheet(
            context: context,
            isScrollControlled: true,
            builder: (BuildContext context) {
              return Container(
                height: MediaQuery.of(context).size.height * 0.80,
                decoration: BoxDecoration(
                  color: Colors.green,
                  borderRadius: BorderRadius.only(
                    topLeft: Radius.circular(30.0),
                    topRight: Radius.circular(30.0),
                  ),
                ),
                child: Center(...),
              );
            },
          );
        },
      );
    }
  }
  </code></pre>
  <p>The resultant widget is the following:
  <a href="https://i.stack.imgur.com/PUAw6.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PUAw6.jpg" alt="enter image description here" /></a></p>
  <p>I want to delete the white spaces in the top border.
  Thank you in advance</p>