Contao\CoreBundle\Test\EventListener\MergeHttpHeadersListenerTest::testHeadersAreMerged PHP Method

    public function testHeadersAreMerged()
    {
        $responseEvent = new FilterResponseEvent($this->mockKernel(), new Request(), HttpKernelInterface::MASTER_REQUEST, new Response());
        /** @var ContaoFrameworkInterface|\PHPUnit_Framework_MockObject_MockObject $framework */
        $framework = $this->getMock('Contao\\CoreBundle\\Framework\\ContaoFrameworkInterface');
        $framework->expects($this->once())->method('isInitialized')->willReturn(true);
        $listener = new MergeHttpHeadersListener($framework);
        $listener->setHeaders(['Content-Type: text/html']);
        $listener->onKernelResponse($responseEvent);
        $response = $responseEvent->getResponse();
        $this->assertTrue($response->headers->has('Content-Type'));
        $this->assertSame('text/html', $response->headers->get('Content-Type'));
    }