Flutter Http high CPU usage

Question

I tried to send a GET request：

Future<void> testHttp() async {
  final response = await http.Request("GET", Uri.parse(url)).send();
  print('testHttp response:${response.statusCode} ');
}

@override
Widget build(BuildContext context) {
  return ElevatedButton(
    onPressed: testHttp,
    child: const Text("Send"),
  );
}

The url points to a file download address, but I ignore the response. And then it cause CPU(i3-9100f) high usage abidingly, unless I read the stream in response.

Looking at DevTool found that garbage collection has been triggered.

Does this response need to be turned off manually? But I can't find anything like close() on response. Or is this a bug?