/// <summary>
/// Presents login screen using the specified <paramref name="viewController"/>.
/// </summary>
/// <param name="viewController">Used to present login screen.</param>
public static void Activate(UIViewController viewController)
{
var loginScreen = new LoginViewController(new TCredentialsProvider(), new TMessages());
var navigationController = new CustomNavigationController(loginScreen);
loginScreen.SetCompletionHandler(() => navigationController.DismissViewController(true, null));
viewController.PresentViewController(navigationController, true, null);
}
