One last comment :smile: (I hope!)

I wonder if we should detect `eventTypes.length == 1 && eventTypes[0] == null` and reset the field to null in that case? (just like if we had never set an event type list).

Of course, they can always set it to `ApplicationEvent` to get all events.

Also, aside from the only element being null, maybe an `Assert.noNullElements()` ??