Where’s the bug?

Where’s the bug?

public virtual void RemoveOfferItems()
{
    for ( int i = 0; i < offerItems.Count; i++ )
    {
        OfferItem offerItem = offerItems[i];
        log.Trace( "offer item: {0}, {1}", offerItem.Id, offerItem.Description );

        offerItems.Remove( offerItem );
        offerItem.Delete();
    }
    Save();
}

But don’t write a test for this…