+ (UIViewController *)findBestViewController:(UIViewController *)vc {
    if (vc.presentedViewController) {
        // Return presented view controller
        return [DQControllerManager findBestViewController:vc.presentedViewController];
        
    } else if ([vc isKindOfClass:[UISplitViewController class]]) {
        // Return right hand side
        UISplitViewController *svc = (UISplitViewController *) vc;
        if (svc.viewControllers.count > 0)
            return [DQControllerManager findBestViewController:svc.viewControllers.lastObject];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UINavigationController class]]) {
        // Return top view
        UINavigationController *svc = (UINavigationController *) vc;
        if (svc.viewControllers.count > 0)
            return [DQControllerManager findBestViewController:svc.topViewController];
        else
            return vc;
        
    } else if ([vc isKindOfClass:[UITabBarController class]]) {
        // Return visible view
        UITabBarController *svc = (UITabBarController *) vc;
        if (svc.viewControllers.count > 0)
            return [DQControllerManager findBestViewController:svc.selectedViewController];
        else
            return vc;
    } else {
        // Unknown view controller type, return last child view controller
        return vc;
    }
}