public function __isset($strKey)
    {
        switch ($strKey) {
            case 'subTemplate':
                return isset($this->subTemplate);

            case 'thumbnailHeight':
                return isset($this->thumbnailHeight);

            case 'thumbnailWidth':
                return isset($this->thumbnailWidth);

            case 'placeholderImage':
                return isset($this->placeholderImage);

            default:
                return parent::__get($strKey);
        }
    }