Sonata\BasketBundle\Controller\Api\BasketController::checkExistingCustomerBasket PHP Method

    protected function checkExistingCustomerBasket($customerId)
    {
        $basket = $this->basketManager->findOneBy(array('customer' => $customerId));
        if ($basket instanceof BasketInterface) {
            throw new HttpException('400', sprintf('Customer (%d) already has a basket', $customerId));
        }
    }