public function testIsXmlHttpRequest() {
$request = new Request();
$this
->assertFalse($request
->isXmlHttpRequest());
$request->headers
->set('X-Requested-With', 'XMLHttpRequest');
$this
->assertTrue($request
->isXmlHttpRequest());
$request->headers
->remove('X-Requested-With');
$this
->assertFalse($request
->isXmlHttpRequest());
}