Getstream Nodejs: TypeError: Cannot read property 'get' of undefined

Question

I'm trying to implement news feed into my app. Yesterday I wrote this GitHub issue中提取rel中的内容，但今天我尝试在自己的应用中实现它，我得到同样的错误：

TypeError: Cannot read property 'get' of undefined

它引用了这些代码行：

let flatFeed = FeedManager.getNewsFeeds(userId)["timeline_flat"];

  flatFeed
    .get({})
    .then(function(body) {
      let activities = body.results;
      return StreamBackend.enrichActivities(activities);
    })
    .then(function(enrichedActivities) {
      return res.render("feed", {
        location: "feed",
        user: req.user,
        activities: enrichedActivities,
        path: req.url
      });
    })
    .catch(next);

这就是我实例化FeedManager的方式

let stream_node = require("getstream-node");
let FeedManager = stream_node.FeedManager;

我在记录FeedManager.getNewsFeeds(userId))

时得到此信息

[ flat: { client:
         { apiKey: 'myapikey',
           apiSecret: 'mysecret',
           appId: 'myappid',
           options: [Object],
           version: 'v1.0',
           fayeUrl: 'https://faye.getstream.io/faye',
           fayeClient: null,
           group: 'unspecified',
           subscriptions: {},
           expireTokens: false,
           location: 'us-east',
           baseUrl: 'https://us-east-api.stream-io-api.com/api/',
           handlers: {},
           browser: false,
           node: true },
        slug: 'flat',
        userId: '5a36b5f8c8b6a1a0b5099cc3',
        id: 'flat:5a36b5f8c8b6a1a0b5099cc3',
        token: '8cQoPLYwlH_qY8vrj7Y8gC7jZ0o',
        feedUrl: 'flat/5a36b5f8c8b6a1a0b5099cc3',
        feedTogether: 'flat5a36b5f8c8b6a1a0b5099cc3',
        signature: 'flat5a36b5f8c8b6a1a0b5099cc3 8cQoPLYwlH_qY8vrj7Y8gC7jZ0o',
        notificationChannel: 'site-32687-feed-flat5a36b5f8c8b6a1a0b5099cc3' },
      aggregated: { client:
         { apiKey: 'mykey',
           apiSecret: 'mysecret',
           appId: 'myappid',
           options: [Object],
           version: 'v1.0',
           fayeUrl: 'https://faye.getstream.io/faye',
           fayeClient: null,
           group: 'unspecified',
           subscriptions: {},
           expireTokens: false,
           location: 'us-east',
           baseUrl: 'https://us-east-api.stream-io-api.com/api/',
           handlers: {},
           browser: false,
           node: true },
        slug: 'aggregated',
        userId: '5a36b5f8c8b6a1a0b5099cc3',
        id: 'aggregated:5a36b5f8c8b6a1a0b5099cc3',
        token: '1BK-vEXYKYHJNYCMeuf5VHRjeG0',
        feedUrl: 'aggregated/5a36b5f8c8b6a1a0b5099cc3',
        feedTogether: 'aggregated5a36b5f8c8b6a1a0b5099cc3',
        signature: 'aggregated5a36b5f8c8b6a1a0b5099cc3 1BK-vEXYKYHJNYCMeuf5VHRjeG0',
        notificationChannel: 'site-32687-feed-aggregated5a36b5f8c8b6a1a0b5099cc3' } ]

跟踪：

TypeError: Cannot read property 'get' of undefined
    at exports.feed_get (/Users/brankozivanovic/Desktop/kafici-api/controllers/userController.js:652:5)
    at Layer.handle [as handle_request] (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/layer.js:95:5)
    at next (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/route.js:137:13)
    at Route.dispatch (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/route.js:112:3)
    at Layer.handle [as handle_request] (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/layer.js:95:5)
    at /Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:281:22
    at param (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:354:14)
    at param (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:365:14)
    at Function.process_params (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:410:3)
    at next (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:275:10)
    at Function.handle (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:174:3)
    at router (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:47:12)
    at Layer.handle [as handle_request] (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:317:13)
    at /Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:284:7
    at Function.process_params (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:335:12)
    at next (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:275:10)
    at Function.handle (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:174:3)
    at router (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:47:12)
    at Layer.handle [as handle_request] (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/layer.js:95:5)
    at trim_prefix (/Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:317:13)
    at /Users/brankozivanovic/Desktop/kafici-api/node_modules/express/lib/router/index.js:284:7