EventListenerYAMLError：此处不允许映射值

Question

当我尝试在python文件上运行dev_appserver时出现以下错误。

  File "/Applications/GoogleAppEngineLauncher.app/Contents/Resources/GoogleAppEngine-default.bundle/Contents/Resources/google_appengine/google/appengine/api/yaml_listener.py", line 213, in _GenerateEventParameters
    raise yaml_errors.EventListenerYAMLError(e)
google.appengine.api.yaml_errors.EventListenerYAMLError: mapping values are not allowed here
  in "cfcdatastore_api.py", line 16, column 38

yaml文件

application: xxx
version: 1
runtime: python27
threadsafe: true
api_version: 1

handlers:
-url: /_ah/xxx/.*
 script: cfcdatastore_api.application

libraries:
-name: endpoints
 version: 1.0

python文件

import endpoints
from protorpc import messages
from protorpc import message_types
from protorpc import remote

from DatastoreEndpoints.models.NewsItem import NewsItem
from DatastoreEndpoints.models.NewsItems import NewsItems

package = "News"

STORED_MESSAGES = NewsItems(items=[
        NewsItem(Title='News Item 1'),
        NewsItem(Title='News Item 2')])


@endpoints.api(name='cfcdatastore', version="v1")
class CFCDatastoreApi(remote.Service):
    @endpoints.method(message_types.VoidMessage, NewsItems,
                      path='messages', http_method='GET',
                      name='newsitems.listNewsitems')
    def news_items_list(self, unused_request):
        return STORED_MESSAGES

    ID_RESOURCE = endpoints.ResourceContainer(
        message_types.VoidMessage,
        id=messages.IntegerField(1, variant=messages.Variant.INT32))

    @endpoints.method(ID_RESOURCE, NewsItem,
                      path='news/{id}',
                      http_method='GET',
                      name='newsitems.getNewsitems')
    def news_items_get(self, request):
        try:
            return STORED_MESSAGES.items[request.id]
        except (IndexError, TypeError):
            raise endpoints.NotFoundException('News %s not found.' %
                                              (request.id))

APPLICATION = endpoints.api_server([CFCDatastoreApi])