anchor.diff:      }
     }
   
  -  Future<bool> _requiresUpdate(
  -      String packageName, String packageVersion) async {
  +  Future<bool> _requiresUpdate(String packageName, String packageVersion,
  +      {bool retryFailed: false}) async {
       final List<PackageVersionAnalysis> list = await _db.lookup([
         _db.emptyKey
             .append(PackageAnalysis, id: packageName)
  
positive.code:         new DateTime.now().toUtc().difference(version.analysisTimestamp);
      if (diff.inDays >= afterDays) return true;
  
      return false;
    }
  }
  
negative.code:         // Check and schedule the latest stable version of each package.
          final Query packageQuery = _db.query(Package)..order('-updated');
          await for (Package p in packageQuery.run()) {
            if (await _requiresUpdate(p.name, p.latestVersion,
                retryFailed: true)) {
              yield new Task(p.name, p.latestVersion, p.updated);
            }
  
  