This works but is a bit unconventional. One common JavaScript idiom is to simply assign an object to the prototype with a property for each method:

```
StripperConstructor.prototype = {
   getPrefs: function(err, trimEmpty) { ... },
   getLine: function(..) { ... }
   // etc.
};
```

In that case I'd also rename `StripperConstructor` to just `Stripper`.