code: public void onUp(HumanInputEvent<?> event) {
  		if (!isRightMouseButton(event)) {
  			ToggleSelectionAction action = new ToggleSelectionAction(mapWidget, pixelTolerance);
  			action.setPriorityToSelectedLayer(priorityToSelectedLayer);
  			action.toggleSingle(getLocation(event, RenderSpace.SCREEN));
  		}
  	}
docs: Toggle selection at the event location.
  
  @param event
  event