AdamWathan\Form\Elements\Checkbox::setOldValue PHP Method

    public function setOldValue($oldValue)
    {
        $this->oldValue = $oldValue;
    }

 public function checkbox($name, $value = 1)
 {
     $checkbox = new Checkbox($name, $value);
     $oldValue = $this->getValueFor($name);
     $checkbox->setOldValue($oldValue);
     return $checkbox;
 }