public function getProductPosition($category_id) {
    $endpoint = $this->apiVersion . "/agent/category/$category_id/position";

    $doReq = function ($client, $opt) use ($endpoint) {
      return ($client->get($endpoint, $opt));
    };

    $result = [];

    try {
      $result = $this->tryAgentRequest($doReq, 'productPosition', 'position');
    }
    catch (ConnectorException $e) {
      throw new \Exception($e->getMessage(), $e->getCode());
    }

    return $result;
  }