public async Task Handle_WhenInvoked_MustSaveNewOrder()
        {
            // Arrange
            var command = new CreateOrderCommandBuilder().Build();
            var subject = CreateSubject();

            // Act
            await subject.Handle(command);

            // Assert
            await repository.Received().Save(
                Arg.Is <Order>(
                    o => o.Id == command.OrderId &&
                    o.GroupId == command.GroupId &&
                    o.SupplierId == command.SupplierId));
        }