public class SampleTest
{
    [Fact]
    public void SampleTest_GetNewItem()
    {
        var myHomeID = new ID();
        var templateID = new ID();
        var template = new TemplateID(templateID);

        using (var db = new Db()
        {
            new DbItem("Home", myHomeID)
        }){
            Item myHomeItem = db.GetItem(myHomeID);
            Item returnItem = myHomeItem.Add("myNewItem", template);

            returnItem.Should().NotBeNull(); //Assert fails because returnItem is null
        }
    }
}