https://api.drupal.org/api/drupal/core%21modules%21locale%21src%21LocaleLookup.php/property/LocaleLookup%3A%3AlanguageManager/11.x
LocaleLookup::$languageManager | Drupal API
drupalapi
https://api.drupal.org/api/drupal/core%21modules%21locale%21src%21LocaleLookup.php/class/LocaleLookup/8.9.x
class LocaleLookup | Drupal API
classdrupalapi