anchor.diff:    List<EventModel> _data;
   
     final NetworkHelper _networkHelper = NetworkHelper();
  -  final Map<String, String> headers = {
  -    "accept": "application/json",
  -  };
   
     EventsService() {
       fetchData();
  
positive.code:     _isLoading = true;
      try {
        /// fetch data
        String _response =
            await _networkHelper.authorizedFetch(endpoint, headers);
  
        /// parse data
        final data = eventModelFromJson(_response);
        _isLoading = false;
        _data = data;
        return true;
      } catch (e) {
        if (e.response != null && e.response.statusCode == 401) {
          if (await getNewToken()) {
            return await fetchData();
          }
        }
        _error = e.toString();
        print(_error);
        _isLoading = false;
        return false;
      }
    }
  
    Future<bool> getNewToken() async {
      final String tokenEndpoint = "https://api-qa.ucsd.edu:8243/token";
      final Map<String, String> tokenHeaders = {
        "content-type": 'application/x-www-form-urlencoded',
        "Authorization":
            "Basic djJlNEpYa0NJUHZ5akFWT0VRXzRqZmZUdDkwYTp2emNBZGFzZWpmaWZiUDc2VUJjNDNNVDExclVh"
      };
      try {
        var response = await _networkHelper.authorizedPost(
            tokenEndpoint, tokenHeaders, "grant_type=client_credentials");
        headers["Authorization"] = "Bearer " + response["access_token"];
        return true;
      } catch (e) {
        _error = e.toString();
        return false;
      }
    }
  
negative.code: 
  class EventsService {
    final String endpoint =
        'https://9tqs71by9h.execute-api.us-west-2.amazonaws.com/qa/v1/events/student-v2';
  
    bool _isLoading = false;
    DateTime _lastUpdated;
  