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));
}