public function items($object = null)
    {
        if (!$this->_items) {
            $this->_initItems();
        }
        
        $items = array();
        
        foreach ($this->_items as $item) {
            if ($object !== null && !$item->isApplicable($object)) {
                continue;
            }
            
            $items[] = $item;
        }
        
        return $items;
    }