private function includeYii()
    {
        if (file_exists($this->_baseYiiFile)) {
            defined('LUYA_YII_VENDOR') ?: define('LUYA_YII_VENDOR', dirname($this->_baseYiiFile));
            
            $baseYiiFolder = LUYA_YII_VENDOR . DIRECTORY_SEPARATOR;
            $luyaYiiFile = $this->getCoreBasePath() . DIRECTORY_SEPARATOR .  'Yii.php';
            
            if (file_exists($luyaYiiFile)) {
                require_once($baseYiiFolder . 'BaseYii.php');
                require_once($luyaYiiFile);
            } else {
                require_once($baseYiiFolder . 'Yii.php');
            }
            
            Yii::setAlias('@luya', $this->getCoreBasePath());
            
            return true;
        }

        throw new Exception("YiiBase file does not exits '".$this->_baseYiiFile."'.");
    }