Bug 417317 Error when running chart example SwingInteractivityViewer.java.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/render/InteractiveRenderer.java
return true;
		}
	}
	public void unregisterAction( StructureSource target, ActionType type )
	{
		if ( iun == null )
			return;
		Object source = getSource( target );
		Set<ActionType> set = targets.get( source );
		if ( set != null && set.size( ) > 1 )
		{
			set.remove( type );
		}
		else
		{
			targets.remove( source );
		}
	}
	public boolean isRegisteredAction( StructureSource target, ActionType type )
	{
		if ( iun == null )
		{
			return false;
		}
		Object source = getSource( target );
		Set<ActionType> set = targets.get( source );
		if ( set != null && set.size( ) > 0 )
		{
			return set.contains( type );
		}