Bug 208412 Enhance Chart Engine to process grouped, uni-dimensional Data
chart/org.eclipse.birt.chart.reportitem/src/org/eclipse/birt/chart/reportitem/ChartReportItemPresentationBase.java
new ChartReportStyleProcessor( handle, this.style ) );
	}
	protected Object getImageToDisplay( )
	{
		if ( getOutputType( ) == OUTPUT_AS_IMAGE )
		{
			return fis;
		}
		else if ( getOutputType( ) == OUTPUT_AS_IMAGE_WITH_MAP )
		{
			return new Object[]{
					fis, imageMap
			};
		}
		else
			throw new IllegalArgumentException( );
	}
	protected void renderToImageFile( GeneratedChartState gcs )
			throws ChartException
	{
		logger.log( ILogger.INFORMATION,
				Messages.getString( "ChartReportItemPresentationImpl.log.onRowSetsRendering" ) ); 
		ByteArrayOutputStream baos = new ByteArrayOutputStream( );
		BufferedOutputStream bos = new BufferedOutputStream( baos );
		idr.setProperty( IDeviceRenderer.FILE_IDENTIFIER, bos );
		idr.setProperty( IDeviceRenderer.UPDATE_NOTIFIER,
				new EmptyUpdateNotifier( cm, gcs.getChartModel( ) ) );
		Generator.instance( ).render( idr, gcs );
		
		try