Unit test custom ActionFilter in ASP.Net MVC

Hi,

I have one filter class

public class MyAuthenticationFilter : ActionFilterAttribute, IAuthenticationFilter
{
    public void OnAuthentication(AuthenticationContext filterContext)
    {
    }

    public void OnAuthenticationChallenge(AuthenticationChallengeContext filterContext)
    {
        string UserName="abc";
        Session["UserName"]=UserName;
    }
}

can you please write some Test case for above class