AutoNumber and Unit Testing

Hi there,

I have an application in which I am using AutoNumber for InvoiceLineId's. In the unit test module, I test everything regarding invoices. An invoiceline object is created in some tests. The result is that my InvoiceLinesId's are not concurrent in my actual database anymore. 

Is there some sort of solution to exclude/rollback autonumbering from my unit tests? I know that I can use calculated integer instead but this is not my preferred choise. 

Thanks for the help!