All classes that implement ContextualLinkInterface in Drupal 9
- class \Drupal\Core\Menu\ContextualLinkDefault implements ContextualLinkInterface
- class \Drupal\config_translation\Plugin\Menu\ContextualLink\ConfigTranslationContextualLink uses StringTranslationTrait
- class \Drupal\menu_test\Plugin\Menu\ContextualLink\TestContextualLink