private UserPrincipal FindUserUsingFilter(string userName, PrincipalContext context)
{
CustomUserPrincipal userPrincipal = new CustomUserPrincipal(context);
userPrincipal.SetUserNameFilter(userName);
PrincipalSearcher searcher = new PrincipalSearcher(userPrincipal);
return(searcher.FindOne() as UserPrincipal);
}