public void HeartBeatUserTest()
{
ITvCardContext ctx = new TvCardContext();
IUser u1 = new User("u1", false, 1);
DateTime oldHB = u1.HeartBeat;
ctx.Add(u1);
ctx.HeartBeatUser(u1);
Assert.AreNotEqual(u1.HeartBeat, oldHB, "heartbeat hasnt changed");
}