Bug 188843 NPE throws out when preview sample report in xls[1203]
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/StyleEngine.java
/*******************************************************************************
 * Copyright (c) 2006 Inetsoft Technology Corp.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *  Inetsoft Technology Corp  - Implementation
 *******************************************************************************/
package org.eclipse.birt.report.engine.emitter.excel;
import java.util.Hashtable;
import java.util.Map;
import java.util.Stack;
import org.eclipse.birt.report.engine.content.IStyle;
/**
 * This class is used to caculate styles for Excel.
 * 
 * 
 */
public class StyleEngine implements IListVisitor