ConcreteMicroKernel example

        if ($this->kernel) {
            $kernel = $this->kernel;
            $this->kernel = null;
            $fs = new Filesystem();
            $fs->remove($kernel->getCacheDir());
        }
    }

    public function test()
    {
        $kernel = $this->kernel = new ConcreteMicroKernel('test', false);
        $kernel->boot();

        $request = Request::create('/');
        $response = $kernel->handle($request);

        $this->assertEquals('halloween', $response->getContent());
        $this->assertEquals('Have a great day!', $kernel->getContainer()->getParameter('halloween'));
        $this->assertInstanceOf(\stdClass::class, $kernel->getContainer()->get('halloween'));
    }

    public function testAsEventSubscriber()
    {