### Question:
StunnerLienzoBoundsPanel implements LienzoPanel { public void destroy() { handlerRegistrationManager.destroy(); view.destroy(); panelBuilder = null; view = null; } @Inject  StunnerLienzoBoundsPanel(final Event<KeyPressEvent> keyPressEvent,
                                    final Event<KeyDownEvent> keyDownEvent,
                                    final Event<KeyUpEvent> keyUpEvent,
                                    final Event<CanvasMouseDownEvent> mouseDownEvent,
                                    final Event<CanvasMouseUpEvent> mouseUpEvent);   StunnerLienzoBoundsPanel(final Event<KeyPressEvent> keyPressEvent,
                             final Event<KeyDownEvent> keyDownEvent,
                             final Event<KeyUpEvent> keyUpEvent,
                             final Event<CanvasMouseDownEvent> mouseDownEvent,
                             final Event<CanvasMouseUpEvent> mouseUpEvent,
                             final HandlerRegistrationImpl registration); StunnerLienzoBoundsPanel setPanelBuilder(final BiFunction<OptionalInt, OptionalInt, LienzoBoundsPanel> panelBuilder); @Override Widget asWidget(); @Override LienzoPanel show(final LienzoLayer layer); @Override LienzoPanel show(final LienzoLayer layer,
                            final int width,
                            final int height); HandlerRegistration register(final HandlerRegistration handler); @Override LienzoPanel focus(); @Override int getWidthPx(); @Override int getHeightPx(); @Override Bounds getLocationConstraints(); @Override LienzoPanel setPixelSize(final int wide,
                                    final int high); @Override void setBackgroundLayer(final Layer layer); void destroy(); @Override LienzoBoundsPanel getView();  }### Answer:
@Test public void testDestroy() { tested.setView(view); tested.destroy(); verify(handlerRegistrationManager, times(1)).destroy(); verify(view, times(1)).destroy(); assertNull(tested.getView()); }