How do I put a StockSeries in front of a BarSeries on a combination chart in BIRT?

Question

Hi all,

Consider the below source code where I create a combination chart with a BarSeries and a StockSeries. The StockSeries generates three identical Candle-stick Stock figures with a box from values 12 to 14 and low and high values 10 and 16. The BarSeries generate three bar figures with heights 11, 13 and 15.

public class StockBarCombination
{

    public final static Chart createStockBarCombination( )
    {
     ChartWithAxes cwaStockBar = ChartWithAxesImpl.create( );

     // Legend
     cwaStockBar.getLegend( ).setVisible( false );

     // X-Axis
     Axis xAxisPrimary = ( (ChartWithAxesImpl) cwaStockBar ).getPrimaryBaseAxes( )[0];

     // Y-Axis
     Axis yAxisPrimary = ( (ChartWithAxesImpl) cwaStockBar ).getPrimaryOrthogonalAxis( xAxisPrimary );


     // Data Set
     TextDataSet categoryValues = TextDataSetImpl.create(
       new String[] { "One", "Two", "Three" }
       );

     StockDataSet dsStockValues = StockDataSetImpl
     .create(new StockEntry[] {
       new StockEntry(12, 10, 16, 14),
       new StockEntry(12, 10, 16, 14),
       new StockEntry(12, 10, 16, 14) });

     NumberDataSet dsBarValues = NumberDataSetImpl.create(
       new double[] { 11, 13, 15 }
       );

     // X-Series
     Series seBase = SeriesImpl.create( );
     seBase.setDataSet( categoryValues );

     SeriesDefinition sdX = SeriesDefinitionImpl.create( );
     xAxisPrimary.getSeriesDefinitions( ).add( sdX );
     sdX.getSeries( ).add( seBase );

     // Y-BarSeries
     BarSeries bs = (BarSeries) BarSeriesImpl.create();
     bs.setDataSet(dsBarValues);

     // Y-StockSeries
     StockSeries ss = (StockSeries) StockSeriesImpl.create( );
     ss.getLineAttributes().setColor(ColorDefinitionImpl.BLUE());
     ss.setDataSet( dsStockValues );

     SeriesDefinition sdY = SeriesDefinitionImpl.create( );
     yAxisPrimary.getSeriesDefinitions( ).add( sdY );
     sdY.getSeries( ).add( bs );
     sdY.getSeries( ).add( ss );

     return cwaStockBar;
    }
}

As you can see on this screenshot , these bars partly obscure and come in front of the Stock figures.

How do I force the StockSeries to come to the front? (I use Eclipse 3.3 and BIRT 2.2.1)

Thanks in advance, Jeroen