MessagesThatStartSagas_1.cs

    public class ShippingPolicy : Saga<ShippingPolicyData>,
        IAmStartedByMessages<OrderAccepted>,
        IHandleMessages<OrderBilled>
    {
        public void Handle(OrderAccepted message)
        {
            Data.OrderId = message.OrderId;
            Data.Accepted = true;
            DispatchOrder();
        }

        public void Handle(OrderBilled message)
        {
            Data.OrderId = message.OrderId;
            Data.Billed = true;
            DispatchOrder();
        }

        void DispatchOrder()
        {
            if (Data.Accepted && Data.Billed)
                Bus.Send<ShipOrder>(m => m.OrderId = Data.OrderId);
        }

        public override void ConfigureHowToFindSaga()
        {
            ConfigureMapping<OrderAccepted>(s=>s.OrderId,m=>m.OrderId);
            ConfigureMapping<OrderBilled>(s => s.OrderId, m => m.OrderId);
        }
    }