anchor.diff:          _dartSdkMap[sdk] = linterVersion;
           print('fetched...');
           print('$sdk : $linterVersion');
  -        print('(consider caching in tool/dart_sdk.yaml)');
  +        print('(consider caching in tool/since/dart_sdk.yaml)');
         }
       }
     }
  
positive.code: import 'crawl.dart';
  
  main() async {
  // TODO(pq): make dynamic or update tests to ensure this stays in sync.
  // Uncomment to (re)generate since/linter.yaml contents.
  //  for (var lint in registeredLints) {
  //    var since = await findSinceLinter(lint.name);
  
negative.code:   var sinceMap = <String, SinceInfo>{};
    for (var lint in registeredLints.map((l) => l.name)) {
      var linterVersion = linterVersionCache[lint];
      if (linterVersion == null) {
        linterVersion = await findSinceLinter(lint);
        if (linterVersion != null) {
          print('fetched...');
          print('$lint : $linterVersion');
          print('(consider caching in tool/since/linter.yaml)');
        }
      }
      sinceMap[lint] = new SinceInfo(
          sinceLinter: linterVersion ?? await findSinceLinter(lint),
          sinceDartSdk: await _sinceSdkForLinter(linterVersion));
  