### Question:
ResizeControlImpl extends AbstractCanvasHandlerRegistrationControl<AbstractCanvasHandler> implements ResizeControl<AbstractCanvasHandler, Element> { @SuppressWarnings("unchecked") protected void onCanvasSelectionEvent(@Observes CanvasSelectionEvent event) { checkNotNull("event", event); if (event.getIdentifiers().size() == 1) { final String uuid = event.getIdentifiers().iterator().next(); if (isSameCanvas(event) && isRegistered(uuid)) { hideALLCPs(); final HasControlPoints<?> hasControlPoints = getControlPointsInstance(uuid); if (!hasControlPoints.areControlsVisible()) { showCPs(hasControlPoints); } } } else if (event.getIdentifiers().size() > 1){ hideALLCPs(); } } protected  ResizeControlImpl(); @Inject  ResizeControlImpl(final CanvasCommandFactory<AbstractCanvasHandler> canvasCommandFactory); @Override @SuppressWarnings("unchecked") void register(final Element element); @Override @SuppressWarnings("unchecked") CommandResult<CanvasViolation> resize(final Element element,
                                                 final double width,
                                                 final double height); @Override void setCommandManagerProvider(final RequiresCommandManager.CommandManagerProvider<AbstractCanvasHandler> provider);  }### Answer:
@Test public void testOnCanvasSelectionEvent() { tested.onCanvasSelectionEvent(elementsSelectedEvent); verify(elementsSelectedEvent, times(2)).getIdentifiers(); }