@Embedded class fields are considered NotNull

[buggins]

class Customer {
    int id;
    string name;
    // Embedded is inferred from type of Address
    Address address;
    this() {
        address = new Address();
    }
}

@Embeddable
class Address {
    string zip;
    string city;
}

If zip is not set, it's impossible to save object
Customer c10 = new Customer();
c10.name = "Customer 10";
sess.save(c10);
Fails on NotNull check for address.zip