deliteful/Toaster widget

Hmm, well what are you trying to test?   The title of the test, "Checking _nonRemovableAreOnlyPersistants behaviour", is hard to understand.  You've also got a comment that

```
// if a message is a non removable then it is persistant
```

But I don't know what you mean by "persistent".   Stays there forever?   So a message without an [x] icon should stay forever?