All classes that implement LanguageManagerInterface in Drupal 8
- class \Drupal\Core\Language\LanguageManager implements LanguageManagerInterface uses DependencySerializationTrait
- class \Drupal\Tests\token\Kernel\MockLanguageManager
- class \Drupal\disable_language\DisableLanguageManager
- class \Drupal\language\ConfigurableLanguageManager implements ConfigurableLanguageManagerInterface