*result = mNext; NS_IF_ADDREF(*result);  mNext = nsnull; return NS_OK; }
*aNext = file; #endif return rv; }
        NS_IMETHOD GetNext(nsISupports **result)        {            nsresult rv;            PRBool hasMore;            rv = HasMoreElements(&hasMore);            if (NS_FAILED(rv)) return rv;            *result = mNext;        // might return nsnull            NS_IF_ADDREF(*result);            mNext = nsnull;            return NS_OK;        }