public function testToStringDoesntMessUpHeaders() {
$headers = new ResponseHeaderBag();
$headers
->set('Location', 'http://www.symfony.com');
$headers
->set('Content-type', 'text/html');
(string) $headers;
$allHeaders = $headers
->allPreserveCase();
$this
->assertEquals(array(
'http://www.symfony.com',
), $allHeaders['Location']);
$this
->assertEquals(array(
'text/html',
), $allHeaders['Content-type']);
}