title: Bad state: Stream has already been listened to Flutter error
body: <p>I am calling an api. I am getting a  streamed response after sending the request. But i cannot parse the response and convert it to String/JSON. This is where I am calling the api.</p>
  
  <pre><code>static Future&lt;String&gt; callDeviceListFetchApi() async {
  Completer completer = new Completer();
  String jsonResponse;
  String url = Constants.BASE_URL + Constants.DEVICE_REGISTER_URL;
  var client = new http.Client();
  var request = new http.Request('GET', Uri.parse(url));
  request.headers[HttpHeaders.CONTENT_TYPE] = 'application/json';
  request.headers[HttpHeaders.AUTHORIZATION] = '&lt;auth code&gt;';
  await client.send(request).then((response) {
    response.stream.bytesToString().then((value) {
      print(value.toString());
      jsonResponse = value.toString();
      completer.complete(jsonResponse);
    });
  }).catchError((error) {
    print(error.toString());
  });
  return completer.future;
  }
  </code></pre>
  
  <p>I am getting the error,
  <code>Bad state: Stream has already been listened to</code> Flutter error. Any idea why this is happening?</p>