Symfony\Component\HttpFoundation\Tests\ResponseTest::testPrepareDoesNothingIfContentTypeIsSet PHP Method

    public function testPrepareDoesNothingIfContentTypeIsSet()
    {
        $response = new Response('foo');
        $response->headers->set('Content-Type', 'text/plain');

        $response->prepare(new Request());

        $this->assertEquals('text/plain; charset=UTF-8', $response->headers->get('content-type'));
    }