public function __construct(LoopInterface $loop, Browser $browser = null)
{
if ($browser === null) {
$b = new Browser($loop);
$browser = $b->withOptions(array('followRedirects' => true, 'maxRedirects' => 10, 'obeySuccessCode' => false));
}
$this->loop = $loop;
$this->browser = $browser;
}