default Selection Decorator
The default selection decorator for this Mark, if you use a custom DatumDecorator you may want to call defaultSelectionDecorator(datum, x, y, drawingZone) to draw the expected sign.
The default selection decorator for this Mark, if you use a custom DatumDecorator you may want to call defaultSelectionDecorator(datum, x, y, drawingZone) to draw the expected sign.