public void ClearTest()
{
ITvCardContext ctx = new TvCardContext();
for (int i = 0; i < 10; i++)
{
IUser u1 = new User("u" + i, false, 1);
ctx.Add(u1);
}
ctx.Clear();
Assert.AreEqual(10, ((TvCardContext)ctx).UsersOld.Count, "oldusers count wrong");
Assert.AreEqual(0, ctx.Users.Length, "users count wrong");
}