<?php

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; under version 2
 * of the License (non-upgradable).
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 * Copyright (c) 2013 (original work) Open Assessment Technologies SA (under the project TAO-PRODUCT);
 *
 *
 */
namespace oat\taoQtiItem\model\qti\expression;

use oat\taoQtiItem\model\qti\expression\Expression;
use oat\taoQtiItem\model\qti\response\Rule;

/**
 * Short description of class oat\taoQtiItem\model\qti\expression\Expression
 *
 * @abstract
 * @access public
 * @author Joel Bout, <joel.bout@tudor.lu>
 * @package taoQTI

 */
abstract class Expression implements Rule
{
    // --- ASSOCIATIONS ---
    // generateAssociationEnd :

    // --- ATTRIBUTES ---

    // --- OPERATIONS ---

    /**
     * Short description of method getRule
     *
     * @access public
     * @author Joel Bout, <joel.bout@tudor.lu>
     * @return string
     */
    public function getRule()
    {
        $returnValue = (string) '';

        
        

        return (string) $returnValue;
    }
}