Bug 121687 Exception throws when export data in table which inside a grid cell.
Description: Exception throws when export data in table which inside a grid cell. Steps to reproduce: 1. insert a grid. 2. insert one table to one grid cell. 3. insert another table to the other grid cell. 4. export data in two tables. Expected result: Data are exported. Actual result: Exception in: ReportEngineService.getMetaData( )
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/parser/EngineIRVisitor.java
/**
	 * report design handle
	 */
	protected ReportDesignHandle handle;
	/**
	 * the CSSEngine
	 */
	protected static final CSSEngine cssEngine = BIRTCSSEngine.getInstance( );
	/**
	 * the inheritable report style
	 */
	StyleDeclaration nonInheritableReportStyle;
	/**
	 * the non-inheritable report style
	 */
	StyleDeclaration inheritableReportStyle;
	/**
	 * constructor
	 * 
	 * @param handle
	 *            the entry point to the DE report design IR
	 * 
	 */
	EngineIRVisitor( ReportDesignHandle handle )
	{
		super( );
		this.handle = handle;
	}
	/**
	 * translate the DE's IR to FPE's IR.