protected function getCache($pk)
    {
        $app = App::getInstance();
        return $app['cache']->getItem($this->dbtable.'/'.$pk->getValue());
    }
protected function getCache($pk)
    {
        $app = App::getInstance();
        return $app['cache']->getItem($this->dbtable.'/'.$pk->getValue());
    }
Get cache item

pk - primary key column