public void Setup()
        {
            supplier = TestSupplier.CreateNaked(session);
            supplier.CreateSampleCore(session);
            supplier.Prices[0].Core.Where(c => c.Producer != null)
            .Each(c => TestAssortment.CheckAndCreate(session, c.Product, c.Producer));
            var client = TestClient.CreateNaked(session);
            var order  = new TestOrder(client.Users[0], supplier.Prices[0]);

            order.Processed = false;
            order.WriteTime = DateTime.Today.AddDays(-1);
            order.AddItem(supplier.Prices[0].Core[0], 1);
            session.Save(order);
            supplier.Maintain(session);
            session.Transaction.Commit();

            calculator = new CostCalculator();

            ratings = RatingCalculator
                      .Caclucated(DateTime.Today.AddDays(-10), DateTime.Today)
                      .Take(3)
                      .ToArray();
        }