/**
* __construct()
*
* @access public
* @param {class} $os The os.
*/
public function __construct(os $os)
{
if (!$os->session_exists()) {
die('Session does not exist!');
}
$this->document_root = $os->get_document_root();
$this->library_dir = $os->get_library_dir();
$this->os = $os;
}