/**
  * Check if a given model is a reference to the
  * same ActiveRecord model by checking its model
  * type and its primary key
  *
  * @param AbstractModel $model
  * @access public
  * @return boolean
  */
 public function isSameModel(AbstractModel $model)
 {
     if ($model->getKey() === $this->getKey() && $model instanceof static) {
         return true;
     }
     return false;
 }