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/ExecutorManager.java
for ( int i = 0; i < NUMBER; i++ )
		{
			freeList[i] = new LinkedList( );
		}
	}
	/**
	 * get item executor
	 * 
	 * @param type
	 *            the executor type
	 * @return item executor
	 */
	public ReportItemExecutor getItemExecutor( int type )
	{
		assert ( type >= 0 ) && ( type < NUMBER );
		if ( !freeList[type].isEmpty( ) )
		{
			
			return (ReportItemExecutor) freeList[type].removeFirst( );
		}
		switch ( type )
		{
			case GRIDITEM :
				return new GridItemExecutor( context, visitor );
			case IMAGEITEM :
				return new ImageItemExecutor( context, visitor );
			case LABELITEM :
				return new LabelItemExecutor( context, visitor );
			case LISTITEM :
				return new ListItemExecutor( context, visitor );