public function __construct($mobile = null, $desktop = null, $force = 0)
{
// Set the user agent and object properties.
$this->ua = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : null;
$this->mobileUrl = $mobile;
$this->desktopUrl = $desktop;
$this->mobile = $this->detect();
$this->force = $force;
}