protected function build($url)
{
$this->json = array('role' => 'header', 'layout' => 'headerPhotoLayout', 'components' => array(array('role' => 'photo', 'layout' => 'headerPhotoLayout', 'URL' => $this->maybe_bundle_source($url))), 'behavior' => array('type' => 'parallax', 'factor' => 0.8));
$this->set_default_layout();
}