getCacheKernel example

'Too many Nesting Levels. Probably one transaction was not closed properly. This may affect following Tests in an unpredictable manner! Current nesting level: "' . $connection->getTransactionNestingLevel() . '".'
        );

        $connection->rollBack();
    }

    public function testCacheHit(): void
    {
        $kernel = $this->getCacheKernel();

        $appUrl = EnvironmentHelper::getVariable('APP_URL');
        static::assertIsString($appUrl);

        $request = $this->createRequest($appUrl);

        $response = $kernel->handle($request);
        static::assertTrue($response->headers->has('x-symfony-cache'));
        static::assertEquals('GET /: miss, store', $response->headers->get('x-symfony-cache'));

        $response = $kernel->handle($request);