protected function executeLoader(LoaderInterface $loader)
    {
        $offset = 0;

        try {

            while ($result = $loader->load($this->limit, $offset)) {

                $this->persist($result);
                $offset += $this->limit;
            }

        } catch (LoaderException $e) {
            $this->getLogger()->error($e->getMessage());
        }
    }