anchor.diff:        headers: {'content-type' : 'application/json; charset="utf-8"'});
   }
   
  +shelf.Response _yamlResponse(String yamlString, {int status: 200}) {
  +  return new shelf.Response(
  +      status,
  +      body: yamlString,
  +      headers: {'content-type' : 'text/yaml; charset="utf-8"'});
  +}
  +
   shelf.Response _atomXmlResponse(String content, {int status: 200}) {
     return new shelf.Response(
         status,
  
positive.code:   }
  
    var package = path.substring(0, slash);
    if (path.substring(slash) == '/versions') {
      return packageVersionsHandler(request, package);
    }
    return _notFoundHandler(request);
  }
  
negative.code: }
  
  
  /// Handles requests for /packages/<package>/versions
  packageVersionsHandler(shelf.Request request, String packageName) async {
    var db = dbService;
    var packageKey = db.emptyKey.append(Package, id: packageName);
  