String pk = primaryKey(); pk = (pk == null) ? "null pk" : pk;
String pk = "null pk"; try { primaryKey(); pk = (pk == null) ? "null pk" : pk; } catch(NullPointerException ex) { cat.warn(ex); }
    public String toString() {        String pk = primaryKey();        pk = (pk == null) ? "null pk" : pk;        return "<" + getClass().getName() + " "+ pk + ">";    }