SzymonPobiega

protected override ValidationResults OnValidate(PurchaseTransaction purchaseTransaction)
{
    return purchaseTransaction
        .With(ValidationCheck)
        .Unless(IsValidateServiceDown)
        .Try(SendMessageToTransecure)
        .InCaseOfException(MarkServiceAsDown)
        .Return(TheResult, OrFailureCodeInCaseOfFailure);
}

SzymonPobiega

[Test]
public void NHibernate_allows_crud_operations()
{
    Create();
    Read();
    Update();
    Delete();
}

private void Create()

SzymonPobiega

//Customer is an aggregate root
public class Customer : AggregateRootMappedByConvention
{
    //Customer contains orders, each of which is uniquely identified hence is an entity
    private readonly List<Order> _orders = new List<Order>();

    public void CreateOrder(int id)
    {
        //Does not create an entity, only publishes event.
        //The entity has localy unique id. Its uniqueness is ensured here.