public function update_langs()
 {
     $active_langs_number = 0;
     foreach (LangsManager::get_installed_langs_map() as $id => $lang) {
         if ($lang->get_configuration()->get_compatibility() == self::NEW_KERNEL_VERSION) {
             $active_langs_number++;
         } else {
             LangsManager::uninstall($id);
             $this->add_information_to_file('lang ' . $id, 'has been uninstalled because : incompatible with new version');
         }
     }
     if (empty($active_langs_number)) {
         LangsManager::install('french');
         $user_accounts_config = UserAccountsConfig::load();
         $user_accounts_config->set_default_lang('french');
         UserAccountsConfig::save();
     }
 }
 private function uninstall($drop_files)
 {
     LangsManager::uninstall($this->id, $drop_files);
 }