public function getCustomerGroupKeyByShopwareIdentifier($identifier)
    {
        /**
         * @var null|Group $group
         */
        $group = $this->repository->find($identifier);

        if (null === $group) {
            return null;
        }

        return $group->getKey();
    }
public function getCustomerGroupKeyByShopwareIdentifier($identifier)
    {
        /**
         * @var null|Group $group
         */
        $group = $this->repository->find($identifier);

        if (null === $group) {
            return null;
        }

        return $group->getKey();
    }
{@inheritdoc}