The controller is not supposed to have a reference to the widget object. Any communication from the controller to the widget is supposed to be done through the report object.
In this method, we are already in the process of defining a report to be sent to the widget.
So, let's simply use the report which is already defined in order to pass the error messages to the widget.

So, I would replace those 3 lines with the following line:
```js
report.errorMessages.push(this.res.errors["40020_WIDGET_AUTOCOMPLETE_VALIDATION"]);
```