Bug 417317 Error when running chart example SwingInteractivityViewer.java.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/InteractiveRenderer.java
{
					series = (Series) src.getSource( );
				}
				else
				{
					series = (Series) ( (WrappedStructureSource) src ).getParent( )
							.getSource( );
				}
				return String.valueOf( series.hashCode( ) );
			}
		}
		else if ( src instanceof WrappedStructureSource )
		{
			return getSource( ( (WrappedStructureSource) src ).getParent( ) );
		}
		return null;
	}
	private boolean isColoredByCategories( )
	{
		return this.iun.getRunTimeModel( ).getLegend( ).getItemType( ) == LegendItemType.CATEGORIES_LITERAL;
	}
	private void hideElement( PrimitiveRenderEvent event )
	{
		Fill fill = event.getBackground( );
		if ( fill != null )
		{
			hideFill( fill );
		}
		LineAttributes lineAttributes = event.getLineAttributes( );
		if ( lineAttributes != null )