public void When_Referenced_It_Is_Added_To_Reference_Fields()
{
var orderMap = new DocumentMap<Order>();
orderMap.Reference(o => o.Customer);
Assert.AreEqual(1, orderMap.GetReferencedFields().Count);
Assert.IsTrue(orderMap.GetReferencedFields().Any(m => m.Name == "Customer" && m.Type == typeof(Customer)));
}