Bug 129144 Support suppressDuplicates property on table row in report engine
See 129143 for detail. This only needs to be supported for data item in a detail row of a table.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ListingElementExecutor.java
/**
	 * create the group header
	 * 
	 * @param list
	 *            listing design
	 * @param index
	 *            group index.
	 * @param emitter
	 *            output emitter
	 */
	abstract protected void accessGroupHeader( ListingDesign list, int index,
			IContentEmitter emitter );
	/**
	 * create the group footer.
	 * 
	 * @param list
	 *            list design
	 * @param index
	 *            group index
	 * @param emitter
	 *            output emitter
	 */
	abstract protected void accessGroupFooter( ListingDesign list, int index,
			IContentEmitter emitter );
	/**
	 * create detail band.
	 * 
	 * @param list
	 *            listing design.
	 * @param emitter