title: How to get a const value in a Model
body: <pre><code>class Model_Item_Review extends \Orm\Model_Soft
  {
  
      const UNCHECK = 0;
      const PUBLISH = 1;
  
      public static function validate()
      {
      $val = Validation::forge('model.item_review_create');
      return $val;
      }
  
  
   }
  </code></pre>
  
  <p>I usually use the function like this \Model_Item_Review::validate();</p>
  
  <p>I wonder how to get the const value of the in the Model like this way.
  eg.<code>\Model_Item_Review::UNCHECK;</code></p>
  
  <p>it seems not work</p>