public void TestAdd()
{
var properties = new PropertiesBufferList();
properties.Properties.Should().BeEmpty();
properties.Add(Core.Properties.Created);
properties.Properties.Should().Equal(new object[] { Core.Properties.Created });
properties.SetValue(Core.Properties.Created, new DateTime(2021, 02, 14, 12, 13, 01));
new Action(() => properties.Add(Core.Properties.Created)).Should().NotThrow("because adding properties again should be tolerate and just not do anything");
properties.Properties.Should().Equal(new object[] { Core.Properties.Created });
properties.GetValue(Core.Properties.Created).Should().Be(new DateTime(2021, 02, 14, 12, 13, 01));
}