//                                                                      ==============
    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);

    //                                                                      ==============
    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);