Bug 188283 Bubbles should be z-sorted by size in Bubble charts
Biggest bubbles should be drawn first so that there is no small bubble hidden by a bigger one.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/DeferredCache.java
}
	/**
	 * Adds marker rendering event to cache.
	 */
	public final void addMarker( PrimitiveRenderEvent pre, int iInstruction,
			double iMarkerSize )
	{
		try
		{
			if ( pre instanceof I3DRenderEvent )
			{
				al3D.add( new MarkerInstruction( this,
						pre.copy( ),
						iInstruction,
						iMarkerSize ) );
			}
			else
			{
				alMarkers.add( new MarkerInstruction( this,
						pre.copy( ),
						iInstruction,
						iMarkerSize ) );
			}
		}
		catch ( ChartException ufex )
		{
			logger.log( ufex );
		}
	}