getContextTokenHeaderName example

$customerId = $this->createCustomer($salesChannelContext, 'info@example.com');

        $browser = $this->createCart($salesChannel['id']);

        $browser->request('PATCH', $this->getRootProxyUrl('/switch-customer'), [
            'salesChannelId' => $salesChannel['id'],
            'customerId' => $customerId,
        ]);

        $response = $this->getBrowser()->getResponse();

        $contextTokenHeaderName = $this->getContextTokenHeaderName();
        static::assertTrue($response->headers->has(PlatformRequest::HEADER_CONTEXT_TOKEN));
        static::assertEquals($browser->getServerParameter($contextTokenHeaderName), $response->headers->get(PlatformRequest::HEADER_CONTEXT_TOKEN));

        static::assertIsString($salesChannel['id']);
        // assert customer is updated in database         $payload = $this->contextPersister->load($response->headers->get(PlatformRequest::HEADER_CONTEXT_TOKEN, ''), $salesChannel['id']);
        static::assertArrayHasKey('customerId', $payload);
        static::assertEquals($customerId, $payload['customerId']);
    }

    public function testSwitchCustomerWithPermissions(): void
    {