NS_PRECONDITION(aResult != nsnull, "null ptr"); if (! aResult) return NS_ERROR_NULL_POINTER;
NS_NewRDFContainer(nsIRDFContainer** aResult){    NS_PRECONDITION(aResult != nsnull, "null ptr");    if (! aResult)        return NS_ERROR_NULL_POINTER;    RDFContainerImpl* result = new RDFContainerImpl();    if (! result)        return NS_ERROR_OUT_OF_MEMORY;    nsresult rv;    rv = result->Init();    if (NS_FAILED(rv)) {        delete result;        return rv;    }    NS_ADDREF(result);    *aResult = result;    return NS_OK;}