public void IsValid()
{
var v = new PastAttribute();
Assert.IsTrue(v.IsValid(DateTime.Now.AddMilliseconds(-1), null));
Assert.IsTrue(v.IsValid(new DateTime?(), null));
Assert.IsTrue(v.IsValid(new DateTime?(DateTime.Now.AddDays(-1)), null));
Assert.IsTrue(v.IsValid(null, null));
Assert.IsTrue(v.IsValid(new DateTime(), null));
Assert.IsFalse(v.IsValid(DateTime.Now, null));
Assert.IsFalse(v.IsValid(DateTime.Now.AddMilliseconds(+1), null));
Assert.IsFalse(v.IsValid(DateTime.Now.ToString(), null));
Assert.IsFalse(v.IsValid(123456, null));
}
