public void TestGetStartDate()
{
var instance = new TestDocument();
Assert.IsNull(configuration.GetStartDate(instance));
configuration.HasStartDate(x => x.StartDate);
Assert.IsNull(configuration.GetStartDate(instance));
instance.StartDate = null;
Assert.IsNull(configuration.GetStartDate(instance));
var now = DateTimeOffset.Now;
instance.StartDate = now;
Assert.AreEqual(now, configuration.GetStartDate(instance));
}