public function moveHigher()
 {
     $higherItem = new SListDecorator($this->higherItem(), $this->scope);
     if ($higherItem === null) {
         return;
     }
     // transaction...
     $higherItem->incrementPosition();
     $this->decrementPosition();
 }
 function testDelete()
 {
     $this->assertEqual(array($this->topics['list_1'], $this->topics['list_2'], $this->topics['list_3'], $this->topics['list_4']), SActiveStore::findAll('Topic', 'forum_id = 1', array('order' => 'position ASC')));
     $topic = new SListDecorator($this->topics['list_2'], 'forum');
     $topic->delete();
     $this->instanciateFixtures();
     $this->assertEqual(array($this->topics['list_1'], $this->topics['list_3'], $this->topics['list_4']), SActiveStore::findAll('Topic', 'forum_id = 1', array('order' => 'position ASC')));
     $this->assertEqual(1, $this->topics['list_1']->position);
     $this->assertEqual(2, $this->topics['list_3']->position);
     $this->assertEqual(3, $this->topics['list_4']->position);
     $topic = new SListDecorator($this->topics['list_1'], 'forum');
     $topic->delete();
     $this->instanciateFixtures();
     $this->assertEqual(array($this->topics['list_3'], $this->topics['list_4']), SActiveStore::findAll('Topic', 'forum_id = 1', array('order' => 'position ASC')));
     $this->assertEqual(1, $this->topics['list_3']->position);
     $this->assertEqual(2, $this->topics['list_4']->position);
 }