/**
  * {@inheritdoc}
  *
  * @param boolean $readonly Set to true to put the model into readonly mode
  * @access public
  * @return void
  */
 public function readonly($readonly = true)
 {
     // Don't allow them to change the readonly state if its frozen
     if ($this->readonly_frozen) {
         return;
     }
     parent::readonly($readonly);
 }