assertTraceContains example

'ETag' => '1234',
                'Cache-Control' => 'public, s-maxage=60',
            ],
            'Hello World',
            null,
            $eventDispatcher
        );

        $this->request('GET', '/');
        $this->assertHttpKernelIsCalled();
        $this->assertEquals(200, $this->response->getStatusCode());
        $this->assertTraceContains('miss');
        $this->assertTraceContains('store');
        $this->cache->terminate($this->request, $this->response);

        sleep(2);

        $this->request('GET', '/');
        $this->assertHttpKernelIsNotCalled();
        $this->assertEquals(200, $this->response->getStatusCode());
        $this->assertTraceContains('fresh');
        $this->assertEquals(2, $this->response->headers->get('Age'));
        $this->cache->terminate($this->request, $this->response);