### Question:
StyleActionAdapter implements ListChangeListener<Action>, Observer { public void close() { myAction.iconIdProperty().removeListener(myIconListener); myAction.colorProperty().removeListener(myColorListener); myAction.getFeatureAction().getActions().removeListener(this); unregisterStyleActionChanges(); } StyleActionAdapter(SimpleFeatureAction action); void close(); @Override void onChanged(Change<? extends Action> c); @Override void update(Observable o, Object arg);  }### Answer:
@Test public void testClose() { FeatureAction action = new FeatureAction(); StyleAction styleAction = new StyleAction(); styleAction.getStyleOptions().setColor(Color.RED); styleAction.getStyleOptions().setIconId(22); action.getActions().add(styleAction); SimpleFeatureAction simpleAction = new SimpleFeatureAction(action); StyleActionAdapter adapter = new StyleActionAdapter(simpleAction); assertEquals(FXUtilities.fromAwtColor(Color.RED), simpleAction.getColor()); assertEquals(22, simpleAction.getIconId()); adapter.close(); simpleAction.setColor(javafx.scene.paint.Color.ORANGE); assertEquals(Color.RED, styleAction.getStyleOptions().getColor()); simpleAction.setIconId(42); assertEquals(22, styleAction.getStyleOptions().getIconId()); assertEquals(0, styleAction.getStyleOptions().countObservers()); }