Possibly wrong handler signature (TypeError: boolean / handler is not a function)

If you receive `TypeError: boolean is not a function` or `TypeError: handler is not a function` after deploying to Amazon Lambda, try changing

```
module.exports.optimizer = processNext();
```

to

```
module.exports.optimizer = function (event, context) {
    processNext();
};
```

I hope this will save somebody's day.