tests for the TranslatorListener

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | 
| License       | MIT
| Doc PR        |
You're right. Don't know why I missed that. Luckily @fabpot fixed already fixed this in 218eb2be0ce57d74cc55b833a84f961b48912dc4. Thanks!