/**
  * Filters the locale and returns the user admin language of the current user, if set.
  *
  * @since   3.0.0
  * @wp-hook locale
  *
  * @param string $locale The current locale.
  *
  * @return string The (filtered) locale.
  */
 public function filter_locale($locale)
 {
     $user_language = $this->language_repository->get_user_language();
     return $user_language ?: (string) $locale;
 }