if (clasz.linkedClass().isNone()) { what = "does not define " + clasz.linkedModule();
if (!root.isClassType() || root.linkedModule() == null) { what = "does not define " + root;
    private void checkValidity(Symbol clasz, String source) {        if (clasz.rawInfo() != this) return;        String what;        if (clasz.linkedClass().isNone()) {            what = "does not define " + clasz.linkedModule();        } else {            if (clasz.linkedModule().moduleClass().rawInfo() != this) return;            what = "defines neither " + clasz + " nor " + clasz.linkedModule();        }        global.error(source + " " + what);    }