All classes that implement TranslationInterface in Drupal 9
- class \Drupal\Core\StringTranslation\TranslationManager implements TranslationInterface, TranslatorInterface
- class \Drupal\Tests\Core\StringTranslation\TestTranslationManager
- class \Drupal\Tests\user\Unit\TestTranslationManager implements TranslationInterface
- class \Drupal\webprofiler\StringTranslation\TranslationManagerWrapper