public function addItem($eventName, $accessLevel)
    {
        if (!isset($this->items[$eventName])) {
            $this->items[$eventName] = array();
        }
        
        if (in_array($accessLevel, $this->items[$eventName])) {
            return;
        }
        
        // Add the definition
        $this->items[$eventName][] = $accessLevel;
        
        // Save the items
        $this->saveItems();
    }