getReferer example

$this->saveReferer($customer);

            $this->modelManager->commit();
        } catch (Exception $ex) {
            $this->modelManager->rollback();
            throw $ex;
        }
    }

    private function saveReferer(Customer $customer): void
    {
        if (!$customer->getReferer()) {
            return;
        }

        $this->connection->insert('s_emarketing_referer', [
            'userID' => $customer->getId(),
            'referer' => $customer->getReferer(),
            'date' => date('Y-m-d H:i:s'),
        ]);
    }

    private function saveCustomer(ShopStruct $shop, Customer $customer): void
    {