title: culture fallback
body: <p>I assume the following code is Correct,</p>
  
  <p>CultureInfo culture = CultureInfo.GetCulture("en-US");
  Assert.IsTrue(culture.GetConsoleFallbackUICulture().Name == "en");</p>
  
  <p>but it is not, culture.GetConsoleFallbackUICulture().Name is still "en-US", I want to know what is the API to get the fallback culture.</p>
  
  <p>Thanks
  Jeff</p>