[Zope] ZCatalogAware: changing catalog name

Hi there, I used the Chapter about "Automatic Cataloging" as base for my own catalog-aware Product. It works as expected, if the ZCatalog has the Id 'Catalog', but doesn't work if I give it an other id (e.q. TestCatalog). Where do can I change the id used for the ZCatalog in my Product/ZClass? TIA Karsten