code: def _QueryChangeFeed(self, collection_link, resource_type, options=None, partition_key_range_id=None):
          
          if options is None:
              options = {}
          options['changeFeed'] = True
  
          resource_key_map = {'Documents' : 'docs'}
  
          # For now, change feed only supports Documents and Partition Key Range resouce type
          if resource_type not in resource_key_map:
              raise NotImplementedError(resource_type + " change feed query is not supported.")
  
          resource_key = resource_key_map[resource_type]
          path = base.GetPathFromLink(collection_link, resource_key)
          collection_id = base.GetResourceIdOrFullNameFromLink(collection_link)
          def fetch_fn(options):
              return self.__QueryFeed(path,
                                      resource_key,
                                      collection_id,
                                      lambda r: r[resource_type],
                                      lambda _, b: b,
                                      None,
                                      options,
                                      partition_key_range_id), self.last_response_headers
          return query_iterable.QueryIterable(self, None, options, fetch_fn, collection_link)
docs: Queries change feed of a resource in a collection.
  
          :param str collection_link:
              The link to the document collection.
          :param str resource_type:
              The type of the resource.
          :param dict options:
              The request options for the request.
          :param str partition_key_range_id:
              Specifies partition key range id.
  
          :return:
              Query Iterable of Documents.
          :rtype:
              query_iterable.QueryIterable