anchor.diff:      return bodySignature == signature;
     }
   
  -  // TODO(wutong): remove the ignores when PullRequestEvent is properly
  -  // exported, https://github.com/SpinlockLabs/github.dart/issues/220
  -  //
  -  // ignore: non_type_as_type_argument
     Future<PullRequestEvent> _getPullRequestEvent(String request) async {
       if (request == null) {
         return null;
       }
       try {
  -      // ignore: undefined_identifier, return_of_invalid_type
         return PullRequestEvent.fromJson(
             json.decode(request) as Map<String, dynamic>);
       } on FormatException {
  
positive.code:   }
  
    Future<void> _handlePullRequest(String rawRequest) async {
      // ignore: undefined_class
      final PullRequestEvent pullRequestEvent =
          await _getPullRequestEvent(rawRequest);
      if (pullRequestEvent == null) {
        throw const BadRequestException('Expected pull request event.');
      }
      // ignore: invalid_assignment
      final String eventAction = pullRequestEvent.action;
      // ignore: invalid_assignment
      final PullRequest pr = pullRequestEvent.pullRequest;
  
      // See the API reference:
  
negative.code: 
  import 'package:crypto/crypto.dart';
  import 'package:github/github.dart';
  import 'package:github/hooks.dart';
  import 'package:meta/meta.dart';
  
  import '../datastore/cocoon_config.dart';
  import '../model/appengine/service_account_info.dart';
  