NodeJS sample code returning errorTypeError

Does anyone have any issues running [this](https://github.com/GantMan/learn-tfjs/blob/master/chapter2/node/node-toxicity/src/index.js) now ?

```
Some errorTypeError: forwardFunc_1 is not a function
node:internal/process/promises:279
triggerUncaughtException(err, true /* fromPromise */);
```

Start with chapter2/node/node-toxicity/src/index.js and reproduce the reported TypeError in the Node.js sample. Check the sample's current execution path and determine what must change for it to run successfully; done means the toxicity example completes without the reported forwardFunc_1 error.

Written by the indexing model from the issue text.