         squareBox.uncheckedBorderColor = .lightGray
         squareBox.borderWidth = 1
         squareBox.valueChanged = { (value) in
-            print("square checkbox value change: \(value)")
+            print("squarebox value change: \(value)")
         }
         view.addSubview(squareBox)
 

        tickBox.borderStyle = .square
        tickBox.checkmarkStyle = .tick
        tickBox.checkmarkSize = 0.7
        view.addSubview(tickBox)
    }

    // target action example
    @objc func circleBoxValueChanged(sender: Checkbox) {
        print("circle box value change: \(sender.isChecked)")
    }

}

        crossBox.borderStyle = .square
        crossBox.checkmarkStyle = .cross
        crossBox.checkmarkSize = 0.7
        crossBox.cornerRadius = 5
        crossBox.valueChanged = { (value) in
            print("crossBox value change: \(value)")
        }
        view.addSubview(crossBox)

        // tick
