/* ====================================================================   Copyright 2002-2004   Apache Software Foundation   Licensed under the Apache License, Version 2.0 (the "License");   you may not use this file except in compliance with the License.   You may obtain a copy of the License at       http://www.apache.org/licenses/LICENSE-2.0   Unless required by applicable law or agreed to in writing, software   distributed under the License is distributed on an "AS IS" BASIS,   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   See the License for the specific language governing permissions and   limitations under the License.==================================================================== */        package org.apache.poi.poifs.property;/** * This interface defines methods for finding and setting sibling * Property instances * * @author Marc Johnson (mjohnson at apache dot org) */public interface Child{    /**     * Get the next Child, if any     *     * @return the next Child; may return null     */    public Child getNextChild();    /**     * Get the previous Child, if any     *     * @return the previous Child; may return null     */    public Child getPreviousChild();    /**     * Set the next Child     *     * @param child the new 'next' child; may be null, which has the     *              effect of saying there is no 'next' child     */    public void setNextChild(final Child child);    /**     * Set the previous Child     *     * @param child the new 'previous' child; may be null, which has     *              the effect of saying there is no 'previous' child     */    public void setPreviousChild(final Child child);}   // end public interface Child