code: public static function setLanguage($language)
      {
          self::$language = $language;
  
          self::$message = [];
  
          self::addMessage(dirname(__FILE__) . '/..');
  
          if (defined('API_ROOT')) {
              self::addMessage(API_ROOT);
          }
      }
docs: 语言设置
  
  @param string $language 翻译包的目录名
  @return void