final Class<? extends RESULT> entityType) {
        assertCBStateValid(cb);
        assertObjectNotNull("entityRowHandler", handler);
        assertSpecifyDerivedReferrerEntityProperty(cb, entityType);
        assertObjectNotNull("entityRowHandler", handler);
        delegateBulkRequest(cb, searchHits -> {
            List<RESULT> list = new ArrayList<>();

        return doSelectEntity(xprepareCBAsPK(id), tp);
    }

    protected UserCB xprepareCBAsPK(String id) {
        assertObjectNotNull("id", id);
        return newConditionBean().acceptPK(id);
    }

    protected <ENTITY extends User> OptionalEntity<ENTITY> doSelectOptionalByPK(String id, Class<? extends ENTITY> tp) {

    //                                                                      ==============
    protected String ln() {
        return DBFluteSystem.ln();
    }

    protected void assertObjectNotNull(String variableName, Object value) {
        if (variableName == null) {
            String msg = "The value should not be null: variableName=null value=" + value;
            throw new IllegalArgumentException(msg);

    //                                                                      ==============
    protected String ln() {
        return DBFluteSystem.ln();
    }

    protected void assertObjectNotNull(String variableName, Object value) {
        if (variableName == null) {
            String msg = "The value should not be null: variableName=null value=" + value;
            throw new IllegalArgumentException(msg);