<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magento.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magento.com for more information.
 *
 * @category    Mage
 * @package     Mage_Sales
 * @copyright  Copyright (c) 2006-2016 X.commerce, Inc. and affiliates (http://www.magento.com)
 * @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/**
 * Base class for invoice total
 *
 * @category    Mage
 * @package     Mage_Sales
 * @author      Magento Core Team <core@magentocommerce.com>
 */
abstract class Mage_Sales_Model_Order_Invoice_Total_Abstract extends Mage_Sales_Model_Order_Total_Abstract
{
    /**
     * Collect invoice subtotal
     *
     * @param Mage_Sales_Model_Order_Invoice $invoice
     * @return Mage_Sales_Model_Order_Invoice_Total_Abstract
     */
    public function collect(Mage_Sales_Model_Order_Invoice $invoice)
    {
        return $this;
    }
}